Convert.ToInt32 メソッド

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(System::String ^ value);

public static int ToInt32 (string value);

public static int ToInt32 (string? value);

static member ToInt32 : string -> int

Public Shared Function ToInt32 (value As String) As Integer

パラメーター

戻り値

value の数値と等価の 32 ビット符号付き整数。value が null の場合は 0 (ゼロ)。

例外

例

次の例では、数値文字列配列内の各要素を整数に変換しようとしています。

string[] values = { "One", "1.34e28", "-26.87", "-18", "-6.00",
                    " 0", "137", "1601.9", Int32.MaxValue.ToString() };
int result;

foreach (string value in values)
{
   try {
      result = Convert.ToInt32(value);
      Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.",
                        value.GetType().Name, value, result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("{0} is outside the range of the Int32 type.", value);
   }
   catch (FormatException) {
      Console.WriteLine("The {0} value '{1}' is not in a recognizable format.",
                        value.GetType().Name, value);
   }
}
// The example displays the following output:
//    The String value 'One' is not in a recognizable format.
//    The String value '1.34e28' is not in a recognizable format.
//    The String value '-26.87' is not in a recognizable format.
//    Converted the String value '-18' to the Int32 value -18.
//    The String value '-6.00' is not in a recognizable format.
//    Converted the String value ' 0' to the Int32 value 0.
//    Converted the String value '137' to the Int32 value 137.
//    The String value '1601.9' is not in a recognizable format.
//    Converted the String value '2147483647' to the Int32 value 2147483647.

let values = 
    [| "One"; "1.34e28"; "-26.87"; "-18"; "-6.00"
       " 0"; "137"; "1601.9"; string Int32.MaxValue |]

for value in values do
    try
        let result = Convert.ToInt32 value
        printfn $"Converted the {value.GetType().Name} value {value} to the {result.GetType().Name} value {result}."
    with
    | :? OverflowException ->
        printfn $"{value} is outside the range of the Int32 type."
    | :? FormatException ->
        printfn $"The {value.GetType().Name} value '{value}' is not in a recognizable format."
// The example displays the following output:
//    The String value 'One' is not in a recognizable format.
//    The String value '1.34e28' is not in a recognizable format.
//    The String value '-26.87' is not in a recognizable format.
//    Converted the String value '-18' to the Int32 value -18.
//    The String value '-6.00' is not in a recognizable format.
//    Converted the String value ' 0' to the Int32 value 0.
//    Converted the String value '137' to the Int32 value 137.
//    The String value '1601.9' is not in a recognizable format.
//    Converted the String value '2147483647' to the Int32 value 2147483647.

Dim values() As String = { "One", "1.34e28", "-26.87", "-18", "-6.00", _
                           " 0", "137", "1601.9", Int32.MaxValue.ToString() }
Dim result As Integer

For Each value As String In values
   Try
      result = Convert.ToInt32(value)
      Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _
                        value.GetType().Name, value, result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("{0} is outside the range of the Int32 type.", value)
   Catch e As FormatException
      Console.WriteLine("The {0} value '{1}' is not in a recognizable format.", _
                        value.GetType().Name, value)
   End Try   
Next                                 
' The example displays the following output:
'    The String value 'One' is not in a recognizable format.
'    The String value '1.34e28' is not in a recognizable format.
'    The String value '-26.87' is not in a recognizable format.
'    Converted the String value '-18' to the Int32 value -18.
'    The String value '-6.00' is not in a recognizable format.
'    Converted the String value ' 0' to the Int32 value 0.
'    Converted the String value '137' to the Int32 value 137.
'    The String value '1601.9' is not in a recognizable format.
'    Converted the String value '2147483647' to the Int32 value 2147483647.

注釈

メソッドの ToInt32(String) 使用は、 メソッドへの渡し value と Int32.Parse(String) 同じです。 value は、現在のカルチャの書式設定規則を使用して解釈されます。

変換が失敗した場合に例外を処理しない場合は、代わりに メソッドを Int32.TryParse 呼び出すことができます。 変換が Boolean 成功したか失敗したかを示す値を返します。

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(System::UInt16 value);

[System.CLSCompliant(false)]
public static int ToInt32 (ushort value);

[<System.CLSCompliant(false)>]
static member ToInt32 : uint16 -> int

Public Shared Function ToInt32 (value As UShort) As Integer

パラメーター

戻り値

value と等価の 32 ビット符号付き整数。

属性

CLSCompliantAttribute

例

次の例では、16 ビット符号なし整数の配列内の各要素を整数に変換します。

ushort[] numbers = { UInt16.MinValue, 121, 340, UInt16.MaxValue };
int result;
foreach (ushort number in numbers)
{
   try {
      result = Convert.ToInt32(number);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    Converted the UInt16 value 0 to the Int32 value 0.
//    Converted the UInt16 value 121 to the Int32 value 121.
//    Converted the UInt16 value 340 to the Int32 value 340.
//    Converted the UInt16 value 65535 to the Int32 value 65535.

let numbers =
    [| UInt16.MinValue; 121us; 340us; UInt16.MaxValue |]

for number in numbers do
    try
        let result = Convert.ToInt32 number
        printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"The {number.GetType().Name} value {number} is outside the range of the Int32 type."
// The example displays the following output:
//    Converted the UInt16 value 0 to the Int32 value 0.
//    Converted the UInt16 value 121 to the Int32 value 121.
//    Converted the UInt16 value 340 to the Int32 value 340.
//    Converted the UInt16 value 65535 to the Int32 value 65535.

Dim numbers() As UShort = { UInt16.MinValue, 121, 340, UInt16.MaxValue }
Dim result As Integer
For Each number As UShort In numbers
   Try
      result = Convert.ToInt32(number)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    Converted the UInt16 value 0 to the Int32 value 0.
'    Converted the UInt16 value 121 to the Int32 value 121.
'    Converted the UInt16 value 340 to the Int32 value 340.
'    Converted the UInt16 value 65535 to the Int32 value 65535.

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(System::UInt32 value);

[System.CLSCompliant(false)]
public static int ToInt32 (uint value);

[<System.CLSCompliant(false)>]
static member ToInt32 : uint32 -> int

Public Shared Function ToInt32 (value As UInteger) As Integer

パラメーター

戻り値

value と等価の 32 ビット符号付き整数。

属性

CLSCompliantAttribute

例外

例

次の例では、符号なし整数の配列内の各要素を符号付き整数に変換しようとします。

uint[] numbers = { UInt32.MinValue, 121, 340, UInt32.MaxValue };
int result;
foreach (uint number in numbers)
{
   try {
      result = Convert.ToInt32(number);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    Converted the UInt32 value 0 to the Int32 value 0.
//    Converted the UInt32 value 121 to the Int32 value 121.
//    Converted the UInt32 value 340 to the Int32 value 340.
//    The UInt32 value 4294967295 is outside the range of the Int32 type.

let numbers =
    [| UInt32.MinValue; 121u; 340u; UInt32.MaxValue |]

for number in numbers do
    try
        let result = Convert.ToInt32 number
        printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"The {number.GetType().Name} value {number} is outside the range of the Int32 type."
// The example displays the following output:
//    Converted the UInt32 value 0 to the Int32 value 0.
//    Converted the UInt32 value 121 to the Int32 value 121.
//    Converted the UInt32 value 340 to the Int32 value 340.
//    The UInt32 value 4294967295 is outside the range of the Int32 type.

Dim numbers() As UInteger = { UInt32.MinValue, 121, 340, UInt32.MaxValue }
Dim result As Integer
For Each number As UInteger In numbers
   Try
      result = Convert.ToInt32(number)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    Converted the UInt32 value 0 to the Int32 value 0.
'    Converted the UInt32 value 121 to the Int32 value 121.
'    Converted the UInt32 value 340 to the Int32 value 340.
'    The UInt32 value 4294967295 is outside the range of the Int32 type.

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(float value);

public static int ToInt32 (float value);

static member ToInt32 : single -> int

Public Shared Function ToInt32 (value As Single) As Integer

パラメーター

戻り値

最も近い 32 ビット符号付き整数に丸められた value。 value が 2 つの整数のちょうど中間にある場合は、偶数が返されます。つまり、4.5 は 4 に変換され、5.5 は 6 に変換されます。

例外

例

次の例では、値の配列 Single 内の各要素を整数に変換しようとします。

float[] values= { Single.MinValue, -1.38e10f, -1023.299f, -12.98f,
                  0f, 9.113e-16f, 103.919f, 17834.191f, Single.MaxValue };
int result;

foreach (float value in values)
{
   try {
      result = Convert.ToInt32(value);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        value.GetType().Name, value, result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("{0} is outside the range of the Int32 type.", value);
   }
}
// The example displays the following output:
//    -3.40282346638529E+38 is outside the range of the Int32 type.
//    -13799999488 is outside the range of the Int32 type.
//    Converted the Double value -1023.29901123047 to the Int32 value -1023.
//    Converted the Double value -12.9799995422363 to the Int32 value -13.
//    Converted the Double value 0 to the Int32 value 0.
//    Converted the Double value 9.11299983940444E-16 to the Int32 value 0.
//    Converted the Double value 103.918998718262 to the Int32 value 104.
//    Converted the Double value 17834.19140625 to the Int32 value 17834.
//    3.40282346638529E+38 is outside the range of the Int32 type.

let values =
    [| Single.MinValue; -1.38e10f; -1023.299f; -12.98f
       0f; 9.113e-16f; 103.919f; 17834.191f; Single.MaxValue |]

for value in values do
    try
        let result = Convert.ToInt32 value
        printfn $"Converted the {value.GetType().Name} value {value} to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"{value} is outside the range of the Int32 type."
// The example displays the following output:
//    -3.40282346638529E+38 is outside the range of the Int32 type.
//    -13799999488 is outside the range of the Int32 type.
//    Converted the Double value -1023.29901123047 to the Int32 value -1023.
//    Converted the Double value -12.9799995422363 to the Int32 value -13.
//    Converted the Double value 0 to the Int32 value 0.
//    Converted the Double value 9.11299983940444E-16 to the Int32 value 0.
//    Converted the Double value 103.918998718262 to the Int32 value 104.
//    Converted the Double value 17834.19140625 to the Int32 value 17834.
//    3.40282346638529E+38 is outside the range of the Int32 type.

Dim values() As Single = { Single.MinValue, -1.38e10, -1023.299, -12.98, _
                           0, 9.113e-16, 103.919, 17834.191, Single.MaxValue }
Dim result As Integer

For Each value As Single In values
   Try
      result = Convert.ToInt32(value)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        value.GetType().Name, value, result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("{0} is outside the range of the Int32 type.", value)
   End Try   
Next                                 
' The example displays the following output:
'    -3.40282346638529E+38 is outside the range of the Int32 type.
'    -13799999488 is outside the range of the Int32 type.
'    Converted the Double value -1023.29901123047 to the Int32 value -1023.
'    Converted the Double value -12.9799995422363 to the Int32 value -13.
'    Converted the Double value 0 to the Int32 value 0.
'    Converted the Double value 9.11299983940444E-16 to the Int32 value 0.
'    Converted the Double value 103.918998718262 to the Int32 value 104.
'    Converted the Double value 17834.19140625 to the Int32 value 17834.
'    3.40282346638529E+38 is outside the range of the Int32 type.

こちらもご覧ください

• Single
• Round

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(System::Object ^ value, IFormatProvider ^ provider);

public static int ToInt32 (object value, IFormatProvider provider);

public static int ToInt32 (object? value, IFormatProvider? provider);

static member ToInt32 : obj * IFormatProvider -> int

Public Shared Function ToInt32 (value As Object, provider As IFormatProvider) As Integer

パラメーター

戻り値

value と等価の 32 ビット符号付き整数。value が null の場合は 0。

例外

例

次の例では、 を実装するクラスと を実装 IConvertible するクラスを定義します IFormatProvider。 を実装するクラスのオブジェクトは、 IConvertible 値の Double 配列を保持します。 各クラスの オブジェクトが メソッドに ToInt32 渡されます。 このメソッドは、 を実装IFormatProviderする オブジェクトを使用して平均のDouble計算方法を決定し、値の配列の平均を返します。

using namespace System;
using namespace System::Collections;

// Define the types of averaging available in the class 
// implementing IConvertible.
public enum class AverageType : short
{
   None = 0,
   GeometricMean = 1,
   ArithmeticMean = 2,
   Median = 3
};


// Pass an instance of this class to methods that require an 
// IFormatProvider. The class instance determines the type of 
// average to calculate.
ref class AverageInfo: public IFormatProvider
{
protected:
   AverageType AvgType;

public:

   // Specify the type of averaging in the constructor.
   AverageInfo( AverageType avgType )
   {
      this->AvgType = avgType;
   }


   // This method returns a reference to the containing object 
   // if an object of AverageInfo type is requested. 
   virtual Object^ GetFormat( Type^ argType )
   {
      if ( argType == AverageInfo::typeid)
            return this;
      else
            return (Object^)0;
   }


   property AverageType TypeOfAverage 
   {

      // Use this property to set or get the type of averaging.
      AverageType get()
      {
         return this->AvgType;
      }

      void set( AverageType value )
      {
         this->AvgType = value;
      }

   }

};


// This class encapsulates an array of double values and implements 
// the IConvertible interface. Most of the IConvertible methods 
// return an average of the array elements in one of three types: 
// arithmetic mean, geometric mean, or median. 
ref class DataSet: public IConvertible
{
private:
   static Object^ null = nullptr;

protected:
   ArrayList^ data;
   AverageInfo^ defaultProvider;

   // This method unboxes a boxed double.
   double UnBoxDouble( Object^ obj )
   {
      return  *static_cast<double^>(obj);
   }


public:

   // Construct the object and add an initial list of values.
   // Create a default format provider.
   DataSet( ... array<Double>^values )
   {
      data = gcnew ArrayList( (Array^)values );
      defaultProvider = gcnew AverageInfo( AverageType::ArithmeticMean );
   }


   // Add additional values with this method.
   int Add( double value )
   {
      data->Add( value );
      return data->Count;
   }


   property double Item[ int ]
   {

      // Get, set, and add values with this indexer property.
      double get( int index )
      {
         if ( index >= 0 && index < data->Count )
                  return UnBoxDouble( data[ index ] );
         else
                  throw gcnew InvalidOperationException( "[DataSet.get] Index out of range." );
      }

      void set( int index, double value )
      {
         if ( index >= 0 && index < data->Count )
                  data[ index ] = value;
         else
         if ( index == data->Count )
                  data->Add( value );
         else
                  throw gcnew InvalidOperationException( "[DataSet.set] Index out of range." );
      }

   }

   property int Count 
   {

      // This property returns the number of elements in the object.
      int get()
      {
         return data->Count;
      }

   }

protected:

   // This method calculates the average of the object's elements.
   double Average( AverageType avgType )
   {
      double SumProd;
      if ( data->Count == 0 )
            return 0.0;

      switch ( avgType )
      {
         case AverageType::GeometricMean:
            SumProd = 1.0;
            for ( int Index = 0; Index < data->Count; Index++ )
               SumProd *= UnBoxDouble( data[ Index ] );
            
            // This calculation will not fail with negative 
            // elements.
            return Math::Sign( SumProd ) * Math::Pow( Math::Abs( SumProd ), 1.0 / data->Count );

         case AverageType::ArithmeticMean:
            SumProd = 0.0;
            for ( int Index = 0; Index < data->Count; Index++ )
               SumProd += UnBoxDouble( data[ Index ] );
            return SumProd / data->Count;

         case AverageType::Median:
            if ( data->Count % 2 == 0 )
                        return (UnBoxDouble( data[ data->Count / 2 ] ) + UnBoxDouble( data[ data->Count / 2 - 1 ] )) / 2.0;
            else
                        return UnBoxDouble( data[ data->Count / 2 ] );

         default:
            return 0.0;
      }
   }


   // Get the AverageInfo object from the caller's format provider,
   // or use the local default.
   AverageInfo^ GetAverageInfo( IFormatProvider^ provider )
   {
      AverageInfo^ avgInfo = nullptr;
      if ( provider != nullptr )
            avgInfo = static_cast<AverageInfo^>(provider->GetFormat( AverageInfo::typeid ));

      if ( avgInfo == nullptr )
            return defaultProvider;
      else
            return avgInfo;
   }


   // Calculate the average and limit the range.
   double CalcNLimitAverage( double min, double max, IFormatProvider^ provider )
   {
      
      // Get the format provider and calculate the average.
      AverageInfo^ avgInfo = GetAverageInfo( provider );
      double avg = Average( avgInfo->TypeOfAverage );
      
      // Limit the range, based on the minimum and maximum values 
      // for the type.
      return avg > max ? max : avg < min ? min : avg;
   }


public:

   // The following elements are required by IConvertible.
   // None of these conversion functions throw exceptions. When
   // the data is out of range for the type, the appropriate
   // MinValue or MaxValue is used.
   virtual TypeCode GetTypeCode()
   {
      return TypeCode::Object;
   }

   virtual bool ToBoolean( IFormatProvider^ provider )
   {
      
      // ToBoolean is false if the dataset is empty.
      if ( data->Count <= 0 )
            return false;
      // For median averaging, ToBoolean is true if any 
      // non-discarded elements are nonzero.
      else
      
      // For median averaging, ToBoolean is true if any 
      // non-discarded elements are nonzero.
      if ( AverageType::Median == GetAverageInfo( provider )->TypeOfAverage )
      {
         if ( data->Count % 2 == 0 )
                  return (UnBoxDouble( data[ data->Count / 2 ] ) != 0.0 || UnBoxDouble( data[ data->Count / 2 - 1 ] ) != 0.0);
         else
                  return UnBoxDouble( data[ data->Count / 2 ] ) != 0.0;
      }
      // For arithmetic or geometric mean averaging, ToBoolean is 
      // true if any element of the dataset is nonzero.  
      else
      {
         for ( int Index = 0; Index < data->Count; Index++ )
            if ( UnBoxDouble( data[ Index ] ) != 0.0 )
                        return true;
         return false;
      }
   }

   virtual Byte ToByte( IFormatProvider^ provider )
   {
      return Convert::ToByte( CalcNLimitAverage( Byte::MinValue, Byte::MaxValue, provider ) );
   }

   virtual Char ToChar( IFormatProvider^ provider )
   {
      return Convert::ToChar( Convert::ToUInt16( CalcNLimitAverage( Char::MinValue, Char::MaxValue, provider ) ) );
   }


   // Convert to DateTime by adding the calculated average as 
   // seconds to the current date and time. A valid DateTime is 
   // always returned.
   virtual DateTime ToDateTime( IFormatProvider^ provider )
   {
      double seconds = Average( GetAverageInfo( provider )->TypeOfAverage );
      try
      {
         return DateTime::Now.AddSeconds( seconds );
      }
      catch ( ArgumentOutOfRangeException^ ) 
      {
         return seconds < 0.0 ? DateTime::MinValue : DateTime::MaxValue;
      }

   }

   virtual Decimal ToDecimal( IFormatProvider^ provider )
   {
      
      // The Double conversion rounds Decimal.MinValue and 
      // Decimal.MaxValue to invalid Decimal values, so the 
      // following limits must be used.
      return Convert::ToDecimal( CalcNLimitAverage(  -79228162514264330000000000000.0, 79228162514264330000000000000.0, provider ) );
   }

   virtual double ToDouble( IFormatProvider^ provider )
   {
      return Average( GetAverageInfo( provider )->TypeOfAverage );
   }

   virtual short ToInt16( IFormatProvider^ provider )
   {
      return Convert::ToInt16( CalcNLimitAverage( Int16::MinValue, Int16::MaxValue, provider ) );
   }

   virtual int ToInt32( IFormatProvider^ provider )
   {
      return Convert::ToInt32( CalcNLimitAverage( Int32::MinValue, Int32::MaxValue, provider ) );
   }

   virtual __int64 ToInt64( IFormatProvider^ provider )
   {
      
      // The Double conversion rounds Int64.MinValue and 
      // Int64.MaxValue to invalid Int64 values, so the following 
      // limits must be used.
      return Convert::ToInt64( CalcNLimitAverage(  -9223372036854775000, 9223372036854775000, provider ) );
   }

   virtual signed char ToSByte( IFormatProvider^ provider )
   {
      return Convert::ToSByte( CalcNLimitAverage( SByte::MinValue, SByte::MaxValue, provider ) );
   }

   virtual float ToSingle( IFormatProvider^ provider )
   {
      return Convert::ToSingle( CalcNLimitAverage( Single::MinValue, Single::MaxValue, provider ) );
   }

   virtual UInt16 ToUInt16( IFormatProvider^ provider )
   {
      return Convert::ToUInt16( CalcNLimitAverage( UInt16::MinValue, UInt16::MaxValue, provider ) );
   }

   virtual UInt32 ToUInt32( IFormatProvider^ provider )
   {
      return Convert::ToUInt32( CalcNLimitAverage( UInt32::MinValue, UInt32::MaxValue, provider ) );
   }

   virtual UInt64 ToUInt64( IFormatProvider^ provider )
   {
      
      // The Double conversion rounds UInt64.MaxValue to an invalid
      // UInt64 value, so the following limit must be used.
      return Convert::ToUInt64( CalcNLimitAverage( 0, 18446744073709550000.0, provider ) );
   }

   virtual Object^ ToType( Type^ conversionType, IFormatProvider^ provider )
   {
      return Convert::ChangeType( Average( GetAverageInfo( provider )->TypeOfAverage ), conversionType );
   }

   virtual String^ ToString( IFormatProvider^ provider )
   {
      AverageType avgType = GetAverageInfo( provider )->TypeOfAverage;
      return String::Format( "( {0}: {1:G10} )", avgType, Average( avgType ) );
   }

};


// Display a DataSet with three different format providers.
void DisplayDataSet( DataSet^ ds )
{
   IFormatProvider^ null = nullptr;
   String^ fmt = "{0,-12}{1,20}{2,20}{3,20}";
   AverageInfo^ median = gcnew AverageInfo( AverageType::Median );
   AverageInfo^ geMean = gcnew AverageInfo( AverageType::GeometricMean );
   
   // Display the dataset elements.
   if ( ds->Count > 0 )
   {
      Console::Write( "\nDataSet: [{0}", ds->Item[ 0 ] );
      for ( int iX = 1; iX < ds->Count; iX++ )
         Console::Write( ", {0}", ds->Item[ iX ] );
      Console::WriteLine( "]\n" );
   }

   Console::WriteLine( fmt, "Convert::", "Default", "Geometric Mean", "Median" );
   Console::WriteLine( fmt, "---------", "-------", "--------------", "------" );
   Console::WriteLine( fmt, "ToBoolean", Convert::ToBoolean( ds, null ), Convert::ToBoolean( ds, geMean ), Convert::ToBoolean( ds, median ) );
   Console::WriteLine( fmt, "ToByte", Convert::ToByte( ds, null ), Convert::ToByte( ds, geMean ), Convert::ToByte( ds, median ) );
   Console::WriteLine( fmt, "ToChar", Convert::ToChar( ds, null ), Convert::ToChar( ds, geMean ), Convert::ToChar( ds, median ) );
   Console::WriteLine( "{0,-12}{1,20:yyyy-MM-dd HH:mm:ss}"
   "{2,20:yyyy-MM-dd HH:mm:ss}{3,20:yyyy-MM-dd HH:mm:ss}", "ToDateTime", Convert::ToDateTime( ds, null ), Convert::ToDateTime( ds, geMean ), Convert::ToDateTime( ds, median ) );
   Console::WriteLine( fmt, "ToDecimal", Convert::ToDecimal( ds, null ), Convert::ToDecimal( ds, geMean ), Convert::ToDecimal( ds, median ) );
   Console::WriteLine( fmt, "ToDouble", Convert::ToDouble( ds, null ), Convert::ToDouble( ds, geMean ), Convert::ToDouble( ds, median ) );
   Console::WriteLine( fmt, "ToInt16", Convert::ToInt16( ds, null ), Convert::ToInt16( ds, geMean ), Convert::ToInt16( ds, median ) );
   Console::WriteLine( fmt, "ToInt32", Convert::ToInt32( ds, null ), Convert::ToInt32( ds, geMean ), Convert::ToInt32( ds, median ) );
   Console::WriteLine( fmt, "ToInt64", Convert::ToInt64( ds, null ), Convert::ToInt64( ds, geMean ), Convert::ToInt64( ds, median ) );
   Console::WriteLine( fmt, "ToSByte", Convert::ToSByte( ds, null ), Convert::ToSByte( ds, geMean ), Convert::ToSByte( ds, median ) );
   Console::WriteLine( fmt, "ToSingle", Convert::ToSingle( ds, null ), Convert::ToSingle( ds, geMean ), Convert::ToSingle( ds, median ) );
   Console::WriteLine( fmt, "ToUInt16", Convert::ToUInt16( ds, null ), Convert::ToUInt16( ds, geMean ), Convert::ToUInt16( ds, median ) );
   Console::WriteLine( fmt, "ToUInt32", Convert::ToUInt32( ds, null ), Convert::ToUInt32( ds, geMean ), Convert::ToUInt32( ds, median ) );
   Console::WriteLine( fmt, "ToUInt64", Convert::ToUInt64( ds, null ), Convert::ToUInt64( ds, geMean ), Convert::ToUInt64( ds, median ) );
}

int main()
{
   Console::WriteLine( "This example of the "
   "Convert::To<Type>( Object*, IFormatProvider* ) methods "
   "\ngenerates the following output. The example "
   "displays the values \nreturned by the methods, "
   "using several IFormatProvider objects.\n" );
   
   // To call a [ParamArray] method in C++, you cannot just
   // list the parameters, you need to build an array.
   array<Double>^dataElem = gcnew array<Double>(6);
   dataElem[ 0 ] = 10.5;
   dataElem[ 1 ] = 22.2;
   dataElem[ 2 ] = 45.9;
   dataElem[ 3 ] = 88.7;
   dataElem[ 4 ] = 156.05;
   dataElem[ 5 ] = 297.6;
   DataSet^ ds1 = gcnew DataSet( dataElem );
   DisplayDataSet( ds1 );
   dataElem = gcnew array<Double>(5);
   dataElem[ 0 ] = 359999.95;
   dataElem[ 1 ] = 425000;
   dataElem[ 2 ] = 499999.5;
   dataElem[ 3 ] = 775000;
   dataElem[ 4 ] = 1695000;
   DataSet^ ds2 = gcnew DataSet( dataElem );
   DisplayDataSet( ds2 );
}

/*
This example of the Convert::To<Type>( Object*, IFormatProvider* ) methods
generates the following output. The example displays the values
returned by the methods, using several IFormatProvider objects.

DataSet: [10.5, 22.2, 45.9, 88.7, 156.05, 297.6]

Convert::                Default      Geometric Mean              Median
---------                -------      --------------              ------
ToBoolean                   True                True                True
ToByte                       103                  59                  67
ToChar                         g                   ;                   C
ToDateTime   2003-05-13 15:30:23 2003-05-13 15:29:39 2003-05-13 15:29:47
ToDecimal       103.491666666667    59.4332135445164                67.3
ToDouble        103.491666666667    59.4332135445164                67.3
ToInt16                      103                  59                  67
ToInt32                      103                  59                  67
ToInt64                      103                  59                  67
ToSByte                      103                  59                  67
ToSingle                103.4917            59.43321                67.3
ToUInt16                     103                  59                  67
ToUInt32                     103                  59                  67
ToUInt64                     103                  59                  67

DataSet: [359999.95, 425000, 499999.5, 775000, 1695000]

Convert::                Default      Geometric Mean              Median
---------                -------      --------------              ------
ToBoolean                   True                True                True
ToByte                       255                 255                 255
ToChar                         ?                   ?                   ?
ToDateTime   2003-05-22 08:05:19 2003-05-20 22:54:57 2003-05-19 10:21:59
ToDecimal              750999.89    631577.237188435            499999.5
ToDouble               750999.89    631577.237188435            499999.5
ToInt16                    32767               32767               32767
ToInt32                   751000              631577              500000
ToInt64                   751000              631577              500000
ToSByte                      127                 127                 127
ToSingle                750999.9            631577.3            499999.5
ToUInt16                   65535               65535               65535
ToUInt32                  751000              631577              500000
ToUInt64                  751000              631577              500000
*/

using System;
using System.Collections;

// Define the types of averaging available in the class
// implementing IConvertible.
public enum AverageType : short
{
    None = 0,
    GeometricMean = 1,
    ArithmeticMean = 2,
    Median = 3
};

// Pass an instance of this class to methods that require an
// IFormatProvider. The class instance determines the type of
// average to calculate.
public class AverageInfo : IFormatProvider
{
    protected AverageType AvgType;

    // Specify the type of averaging in the constructor.
    public AverageInfo( AverageType avgType )
    {
        this.AvgType = avgType;
    }

    // This method returns a reference to the containing object
    // if an object of AverageInfo type is requested.
    public object GetFormat( Type argType )
    {
        if ( argType == typeof( AverageInfo ) )
            return this;
        else
            return null;
    }

    // Use this property to set or get the type of averaging.
    public AverageType TypeOfAverage
    {
        get { return this.AvgType; }
        set { this.AvgType = value; }
    }
}

// This class encapsulates an array of double values and implements
// the IConvertible interface. Most of the IConvertible methods
// return an average of the array elements in one of three types:
// arithmetic mean, geometric mean, or median.
public class DataSet : IConvertible
{
    protected ArrayList     data;
    protected AverageInfo   defaultProvider;

    // Construct the object and add an initial list of values.
    // Create a default format provider.
    public DataSet( params double[ ] values )
    {
        data = new ArrayList( values );
        defaultProvider =
            new AverageInfo( AverageType.ArithmeticMean );
    }

    // Add additional values with this method.
    public int Add( double value )
    {
        data.Add( value );
        return data.Count;
    }

    // Get, set, and add values with this indexer property.
    public double this[ int index ]
    {
        get
        {
            if( index >= 0 && index < data.Count )
                return (double)data[ index ];
            else
                throw new InvalidOperationException(
                    "[DataSet.get] Index out of range." );
        }
        set
        {
            if( index >= 0 && index < data.Count )
                data[ index ] = value;

            else if( index == data.Count )
                data.Add( value );
            else
                throw new InvalidOperationException(
                    "[DataSet.set] Index out of range." );
        }
    }

    // This property returns the number of elements in the object.
    public int Count
    {
        get { return data.Count; }
    }

    // This method calculates the average of the object's elements.
    protected double Average( AverageType avgType )
    {
        double  SumProd;

        if( data.Count == 0 )
            return 0.0;

        switch( avgType )
        {
            case AverageType.GeometricMean:

                SumProd = 1.0;
                for( int Index = 0; Index < data.Count; Index++ )
                    SumProd *= (double)data[ Index ];

                // This calculation will not fail with negative
                // elements.
                return Math.Sign( SumProd ) * Math.Pow(
                    Math.Abs( SumProd ), 1.0 / data.Count );

            case AverageType.ArithmeticMean:

                SumProd = 0.0;
                for( int Index = 0; Index < data.Count; Index++ )
                    SumProd += (double)data[ Index ];

                return SumProd / data.Count;

            case AverageType.Median:

                if( data.Count % 2 == 0 )
                    return ( (double)data[ data.Count / 2 ] +
                        (double)data[ data.Count / 2 - 1 ] ) / 2.0;
                else
                    return (double)data[ data.Count / 2 ];

            default:
                return 0.0;
        }
    }

    // Get the AverageInfo object from the caller's format provider,
    // or use the local default.
    protected AverageInfo GetAverageInfo( IFormatProvider provider )
    {
        AverageInfo avgInfo = null;

        if( provider != null )
            avgInfo = (AverageInfo)provider.GetFormat(
                typeof( AverageInfo ) );

        if ( avgInfo == null )
            return defaultProvider;
        else
            return avgInfo;
    }

    // Calculate the average and limit the range.
    protected double CalcNLimitAverage( double min, double max,
        IFormatProvider provider )
    {
        // Get the format provider and calculate the average.
        AverageInfo avgInfo = GetAverageInfo( provider );
        double avg = Average( avgInfo.TypeOfAverage );

        // Limit the range, based on the minimum and maximum values
        // for the type.
        return avg > max ? max : avg < min ? min : avg;
    }

    // The following elements are required by IConvertible.

    // None of these conversion functions throw exceptions. When
    // the data is out of range for the type, the appropriate
    // MinValue or MaxValue is used.
    public TypeCode GetTypeCode( )
    {
        return TypeCode.Object;
    }

    public bool ToBoolean( IFormatProvider provider )
    {
        // ToBoolean is false if the dataset is empty.
        if( data.Count <= 0 )
        {
            return false;
        }

        // For median averaging, ToBoolean is true if any
        // non-discarded elements are nonzero.
        else if( AverageType.Median ==
            GetAverageInfo( provider ).TypeOfAverage )
        {
            if (data.Count % 2 == 0 )
                return ( (double)data[ data.Count / 2 ] != 0.0 ||
                    (double)data[ data.Count / 2 - 1 ] != 0.0 );
            else
                return (double)data[ data.Count / 2 ] != 0.0;
        }

        // For arithmetic or geometric mean averaging, ToBoolean is
        // true if any element of the dataset is nonzero.
        else
        {
            for( int Index = 0; Index < data.Count; Index++ )
                if( (double)data[ Index ] != 0.0 )
                    return true;
            return false;
        }
    }

    public byte ToByte( IFormatProvider provider )
    {
        return Convert.ToByte( CalcNLimitAverage(
            Byte.MinValue, Byte.MaxValue, provider ) );
    }

    public char ToChar( IFormatProvider provider )
    {
        return Convert.ToChar( Convert.ToUInt16( CalcNLimitAverage(
            Char.MinValue, Char.MaxValue, provider ) ) );
    }

    // Convert to DateTime by adding the calculated average as
    // seconds to the current date and time. A valid DateTime is
    // always returned.
    public DateTime ToDateTime( IFormatProvider provider )
    {
        double seconds =
            Average( GetAverageInfo( provider ).TypeOfAverage );
        try
        {
            return DateTime.Now.AddSeconds( seconds );
        }
        catch( ArgumentOutOfRangeException )
        {
            return seconds < 0.0 ? DateTime.MinValue : DateTime.MaxValue;
        }
    }

    public decimal ToDecimal( IFormatProvider provider )
    {
        // The Double conversion rounds Decimal.MinValue and
        // Decimal.MaxValue to invalid Decimal values, so the
        // following limits must be used.
        return Convert.ToDecimal( CalcNLimitAverage(
            -79228162514264330000000000000.0,
            79228162514264330000000000000.0, provider ) );
    }

    public double ToDouble( IFormatProvider provider )
    {
        return Average( GetAverageInfo(provider).TypeOfAverage );
    }

    public short ToInt16( IFormatProvider provider )
    {
        return Convert.ToInt16( CalcNLimitAverage(
            Int16.MinValue, Int16.MaxValue, provider ) );
    }

    public int ToInt32( IFormatProvider provider )
    {
        return Convert.ToInt32( CalcNLimitAverage(
            Int32.MinValue, Int32.MaxValue, provider ) );
    }

    public long ToInt64( IFormatProvider provider )
    {
        // The Double conversion rounds Int64.MinValue and
        // Int64.MaxValue to invalid Int64 values, so the following
        // limits must be used.
        return Convert.ToInt64( CalcNLimitAverage(
            -9223372036854775000, 9223372036854775000, provider ) );
    }

    public SByte ToSByte( IFormatProvider provider )
    {
        return Convert.ToSByte( CalcNLimitAverage(
            SByte.MinValue, SByte.MaxValue, provider ) );
    }

    public float ToSingle( IFormatProvider provider )
    {
        return Convert.ToSingle( CalcNLimitAverage(
            Single.MinValue, Single.MaxValue, provider ) );
    }

    public UInt16 ToUInt16( IFormatProvider provider )
    {
        return Convert.ToUInt16( CalcNLimitAverage(
            UInt16.MinValue, UInt16.MaxValue, provider ) );
    }

    public UInt32 ToUInt32( IFormatProvider provider )
    {
        return Convert.ToUInt32( CalcNLimitAverage(
            UInt32.MinValue, UInt32.MaxValue, provider ) );
    }

    public UInt64 ToUInt64( IFormatProvider provider )
    {
        // The Double conversion rounds UInt64.MaxValue to an invalid
        // UInt64 value, so the following limit must be used.
        return Convert.ToUInt64( CalcNLimitAverage(
            0, 18446744073709550000.0, provider ) );
    }

    public object ToType( Type conversionType,
        IFormatProvider provider )
    {
        return Convert.ChangeType( Average(
            GetAverageInfo( provider ).TypeOfAverage ),
            conversionType );
    }

    public string ToString( IFormatProvider provider )
    {
        AverageType avgType = GetAverageInfo( provider ).TypeOfAverage;
        return String.Format( "( {0}: {1:G10} )", avgType,
            Average( avgType ) );
    }
}

class IConvertibleProviderDemo
{
    // Display a DataSet with three different format providers.
    public static void DisplayDataSet( DataSet ds )
    {
        string      fmt    = "{0,-12}{1,20}{2,20}{3,20}";
        AverageInfo median = new AverageInfo( AverageType.Median );
        AverageInfo geMean =
            new AverageInfo( AverageType.GeometricMean );

         // Display the dataset elements.
        if( ds.Count > 0 )
        {
            Console.Write( "\nDataSet: [{0}", ds[ 0 ] );
            for( int iX = 1; iX < ds.Count; iX++ )
                Console.Write( ", {0}", ds[ iX ] );
            Console.WriteLine( "]\n" );
        }

        Console.WriteLine( fmt, "Convert.", "Default",
            "Geometric Mean", "Median");
        Console.WriteLine( fmt, "--------", "-------",
            "--------------", "------");
        Console.WriteLine( fmt, "ToBoolean",
            Convert.ToBoolean( ds, null ),
            Convert.ToBoolean( ds, geMean ),
            Convert.ToBoolean( ds, median ) );
        Console.WriteLine( fmt, "ToByte",
            Convert.ToByte( ds, null ),
            Convert.ToByte( ds, geMean ),
            Convert.ToByte( ds, median ) );
        Console.WriteLine( fmt, "ToChar",
            Convert.ToChar( ds, null ),
            Convert.ToChar( ds, geMean ),
            Convert.ToChar( ds, median ) );
        Console.WriteLine( "{0,-12}{1,20:yyyy-MM-dd HH:mm:ss}" +
            "{2,20:yyyy-MM-dd HH:mm:ss}{3,20:yyyy-MM-dd HH:mm:ss}",
            "ToDateTime", Convert.ToDateTime( ds, null ),
            Convert.ToDateTime( ds, geMean ),
            Convert.ToDateTime( ds, median ) );
        Console.WriteLine( fmt, "ToDecimal",
            Convert.ToDecimal( ds, null ),
            Convert.ToDecimal( ds, geMean ),
            Convert.ToDecimal( ds, median ) );
        Console.WriteLine( fmt, "ToDouble",
            Convert.ToDouble( ds, null ),
            Convert.ToDouble( ds, geMean ),
            Convert.ToDouble( ds, median ) );
        Console.WriteLine( fmt, "ToInt16",
            Convert.ToInt16( ds, null ),
            Convert.ToInt16( ds, geMean ),
            Convert.ToInt16( ds, median ) );
        Console.WriteLine( fmt, "ToInt32",
            Convert.ToInt32( ds, null ),
            Convert.ToInt32( ds, geMean ),
            Convert.ToInt32( ds, median ) );
        Console.WriteLine( fmt, "ToInt64",
            Convert.ToInt64( ds, null ),
            Convert.ToInt64( ds, geMean ),
            Convert.ToInt64( ds, median ) );
        Console.WriteLine( fmt, "ToSByte",
            Convert.ToSByte( ds, null ),
            Convert.ToSByte( ds, geMean ),
            Convert.ToSByte( ds, median ) );
        Console.WriteLine( fmt, "ToSingle",
            Convert.ToSingle( ds, null ),
            Convert.ToSingle( ds, geMean ),
            Convert.ToSingle( ds, median ) );
        Console.WriteLine( fmt, "ToUInt16",
            Convert.ToUInt16( ds, null ),
            Convert.ToUInt16( ds, geMean ),
            Convert.ToUInt16( ds, median ) );
        Console.WriteLine( fmt, "ToUInt32",
            Convert.ToUInt32( ds, null ),
            Convert.ToUInt32( ds, geMean ),
            Convert.ToUInt32( ds, median ) );
        Console.WriteLine( fmt, "ToUInt64",
            Convert.ToUInt64( ds, null ),
            Convert.ToUInt64( ds, geMean ),
            Convert.ToUInt64( ds, median ) );
    }

    public static void Main( )
    {
        Console.WriteLine( "This example of " +
            "the Convert.To<Type>( object, IFormatProvider ) methods " +
            "\ngenerates the following output. The example " +
            "displays the values \nreturned by the methods, " +
            "using several IFormatProvider objects.\n" );

        DataSet ds1 = new DataSet(
            10.5, 22.2, 45.9, 88.7, 156.05, 297.6 );
        DisplayDataSet( ds1 );

        DataSet ds2 = new DataSet(
            359999.95, 425000, 499999.5, 775000, 1695000 );
        DisplayDataSet( ds2 );
    }
}

/*
This example of the Convert.To<Type>( object, IFormatProvider ) methods
generates the following output. The example displays the values
returned by the methods, using several IFormatProvider objects.

DataSet: [10.5, 22.2, 45.9, 88.7, 156.05, 297.6]

Convert.                 Default      Geometric Mean              Median
--------                 -------      --------------              ------
ToBoolean                   True                True                True
ToByte                       103                  59                  67
ToChar                         g                   ;                   C
ToDateTime   2003-05-13 15:04:12 2003-05-13 15:03:28 2003-05-13 15:03:35
ToDecimal       103.491666666667    59.4332135445164                67.3
ToDouble        103.491666666667    59.4332135445164                67.3
ToInt16                      103                  59                  67
ToInt32                      103                  59                  67
ToInt64                      103                  59                  67
ToSByte                      103                  59                  67
ToSingle                103.4917            59.43321                67.3
ToUInt16                     103                  59                  67
ToUInt32                     103                  59                  67
ToUInt64                     103                  59                  67

DataSet: [359999.95, 425000, 499999.5, 775000, 1695000]

Convert.                 Default      Geometric Mean              Median
--------                 -------      --------------              ------
ToBoolean                   True                True                True
ToByte                       255                 255                 255
ToChar                         ?                   ?                   ?
ToDateTime   2003-05-22 07:39:08 2003-05-20 22:28:45 2003-05-19 09:55:48
ToDecimal              750999.89    631577.237188435            499999.5
ToDouble               750999.89    631577.237188435            499999.5
ToInt16                    32767               32767               32767
ToInt32                   751000              631577              500000
ToInt64                   751000              631577              500000
ToSByte                      127                 127                 127
ToSingle                750999.9            631577.3            499999.5
ToUInt16                   65535               65535               65535
ToUInt32                  751000              631577              500000
ToUInt64                  751000              631577              500000
*/

open System
open System.Collections

// Define the types of averaging available in the class
// implementing IConvertible.
type AverageType =
    | None = 0s
    | GeometricMean = 1s
    | ArithmeticMean = 2s
    | Median = 3s

// Pass an instance of this class to methods that require an
// IFormatProvider. The class instance determines the type of
// average to calculate.
[<AllowNullLiteral>]
type AverageInfo(avgType: AverageType) =
    // Use this property to set or get the type of averaging.
    member val TypeOfAverage = avgType with get, set 
    
    interface IFormatProvider with
        // This method returns a reference to the containing object
        // if an object of AverageInfo type is requested.
        member this.GetFormat(argType: Type) =
            if argType = typeof<AverageInfo> then
                this
            else
                null

// This class encapsulates an array of double values and implements
// the IConvertible interface. Most of the IConvertible methods
// an average of the array elements in one of three types:
// arithmetic mean, geometric mean, or median.
type DataSet([<ParamArray>] values: double[]) =
    let data = ResizeArray values
    let defaultProvider =
        AverageInfo AverageType.ArithmeticMean

    // Add additional values with this method.
    member _.Add(value: double) =
        data.Add value
        data.Count

    // Get, set, and add values with this indexer property.
    member _.Item
        with get (index) =
            if index >= 0 && index < data.Count then
                data[index]
            else
                raise (InvalidOperationException "[DataSet.get] Index out of range.")
        and set index value =
            if index >= 0 && index < data.Count then
                data[index] <- value
            elif index = data.Count then
                data.Add value
            else
                raise (InvalidOperationException "[DataSet.set] Index out of range.")

    // This property returns the number of elements in the object.
    member _.Count =
        data.Count

    // This method calculates the average of the object's elements.
    member _.Average(avgType: AverageType) =
        if data.Count = 0 then
            0.0
        else
            match avgType with
            | AverageType.GeometricMean ->
                let sumProd =
                    Seq.reduce ( * ) data
                
                // This calculation will not fail with negative
                // elements.
                (sign sumProd |> float) * Math.Pow(abs sumProd, 1.0 / (float data.Count))

            | AverageType.ArithmeticMean ->
                Seq.average data

            | AverageType.Median ->
                if data.Count % 2 = 0 then
                    (data[data.Count / 2] + data[data.Count / 2 - 1]) / 2.0
                else
                    data[ data.Count / 2]
            | _ ->
                0.0

    // Get the AverageInfo object from the caller's format provider,
    // or use the local default.
    member _.GetAverageInfo(provider: IFormatProvider) =
        let avgInfo =
            if provider <> null then
                provider.GetFormat typeof<AverageInfo> :?> AverageInfo
            else 
                null

        if avgInfo = null then
            defaultProvider
        else
            avgInfo

    // Calculate the average and limit the range.
    member this.CalcNLimitAverage(min: double, max: double, provider: IFormatProvider) =
        // Get the format provider and calculate the average.
        let avgInfo = this.GetAverageInfo provider
        let avg = this.Average avgInfo.TypeOfAverage

        // Limit the range, based on the minimum and maximum values
        // for the type.
        if avg > max then max elif avg < min then min else avg

    // The following elements are required by IConvertible.
    interface IConvertible with
        // None of these conversion functions throw exceptions. When
        // the data is out of range for the type, the appropriate
        // MinValue or MaxValue is used.
        member _.GetTypeCode() =
            TypeCode.Object

        member this.ToBoolean(provider: IFormatProvider) =
            // ToBoolean is false if the dataset is empty.
            if data.Count <= 0 then
                false

            // For median averaging, ToBoolean is true if any
            // non-discarded elements are nonzero.
            elif AverageType.Median = this.GetAverageInfo(provider).TypeOfAverage then
                if data.Count % 2 = 0 then
                    (data[data.Count / 2] <> 0.0 || data[data.Count / 2 - 1] <> 0.0)
                else
                    data[data.Count / 2] <> 0.0

            // For arithmetic or geometric mean averaging, ToBoolean is
            // true if any element of the dataset is nonzero.
            else
                Seq.exists (fun x -> x <> 0.0) data

        member this.ToByte(provider: IFormatProvider) =
            Convert.ToByte(this.CalcNLimitAverage(float Byte.MinValue, float Byte.MaxValue, provider) )

        member this.ToChar(provider: IFormatProvider) =
            Convert.ToChar(Convert.ToUInt16(this.CalcNLimitAverage(float Char.MinValue, float Char.MaxValue, provider) ) )

        // Convert to DateTime by adding the calculated average as
        // seconds to the current date and time. A valid DateTime is
        // always returned.
        member this.ToDateTime(provider: IFormatProvider) =
            let seconds = this.Average(this.GetAverageInfo(provider).TypeOfAverage)
            try
                DateTime.Now.AddSeconds seconds
            with :? ArgumentOutOfRangeException ->
                if seconds < 0.0 then DateTime.MinValue else DateTime.MaxValue

        member this.ToDecimal(provider: IFormatProvider) =
            // The Double conversion rounds Decimal.MinValue and
            // Decimal.MaxValue to invalid Decimal values, so the
            // following limits must be used.
            Convert.ToDecimal(this.CalcNLimitAverage(-79228162514264330000000000000.0, 79228162514264330000000000000.0, provider) )

        member this.ToDouble(provider: IFormatProvider) =
            this.Average(this.GetAverageInfo(provider).TypeOfAverage)

        member this.ToInt16(provider: IFormatProvider) =
            Convert.ToInt16(this.CalcNLimitAverage(float Int16.MinValue, float Int16.MaxValue, provider) )

        member this.ToInt32(provider: IFormatProvider) =
            Convert.ToInt32(this.CalcNLimitAverage(Int32.MinValue, Int32.MaxValue, provider) )

        member this.ToInt64(provider: IFormatProvider) =
            // The Double conversion rounds Int64.MinValue and
            // Int64.MaxValue to invalid Int64 values, so the following
            // limits must be used.
            Convert.ToInt64(this.CalcNLimitAverage(-9223372036854775000., 9223372036854775000., provider) )

        member this.ToSByte(provider: IFormatProvider) =
            Convert.ToSByte(this.CalcNLimitAverage(float SByte.MinValue, float SByte.MaxValue, provider) )

        member this.ToSingle(provider: IFormatProvider) =
            Convert.ToSingle(this.CalcNLimitAverage(float Single.MinValue, float Single.MaxValue, provider) )

        member this.ToUInt16(provider: IFormatProvider) =
            Convert.ToUInt16(this.CalcNLimitAverage(float UInt16.MinValue, float UInt16.MaxValue, provider) )

        member this.ToUInt32(provider: IFormatProvider) =
            Convert.ToUInt32(this.CalcNLimitAverage(float UInt32.MinValue, float UInt32.MaxValue, provider) )

        member this.ToUInt64(provider: IFormatProvider) =
            // The Double conversion rounds UInt64.MaxValue to an invalid
            // UInt64 value, so the following limit must be used.
            Convert.ToUInt64(this.CalcNLimitAverage(0, 18446744073709550000.0, provider) )

        member this.ToType(conversionType: Type, provider: IFormatProvider) =
            Convert.ChangeType(this.Average(this.GetAverageInfo(provider).TypeOfAverage), conversionType)

        member this.ToString(provider: IFormatProvider) =
            let avgType = this.GetAverageInfo(provider).TypeOfAverage
            $"( {avgType}: {this.Average avgType:G10} )"                

// Display a DataSet with three different format providers.
let displayDataSet (ds: DataSet) =
    let fmt obj1 obj2 obj3 obj4 = printfn $"{obj1,-12}{obj2,20}{obj3,20}{obj4,20}"
    let median = AverageInfo AverageType.Median
    let geMean =
        AverageInfo AverageType.GeometricMean

    // Display the dataset elements.
    if ds.Count > 0 then
        printf $"\nDataSet: [{ds[0]}"
        for i = 1 to ds.Count - 1 do
            printf $", {ds[i]}"
        printfn "]\n"

    fmt "Convert." "Default" "Geometric Mean" "Median"
    fmt "--------" "-------" "--------------" "------"
    fmt "ToBoolean"
        (Convert.ToBoolean(ds, null))
        (Convert.ToBoolean(ds, geMean))
        (Convert.ToBoolean(ds, median))
    fmt "ToByte"
        (Convert.ToByte(ds, null))
        (Convert.ToByte(ds, geMean))
        (Convert.ToByte(ds, median))
    fmt "ToChar"
        (Convert.ToChar(ds, null))
        (Convert.ToChar(ds, geMean))
        (Convert.ToChar(ds, median))
    printfn $"""{"ToDateTime",-12}{Convert.ToDateTime(ds, null).ToString "20:yyyy-MM-dd HH:mm:ss"}{Convert.ToDateTime(ds, geMean).ToString "20:yyyy-MM-dd HH:mm:ss"}{Convert.ToDateTime(ds, median).ToString "20:yyyy-MM-dd HH:mm:ss"}"""

    fmt "ToDecimal"
        (Convert.ToDecimal(ds, null))
        (Convert.ToDecimal(ds, geMean))
        (Convert.ToDecimal(ds, median))
    fmt "ToDouble"
        (Convert.ToDouble(ds, null))
        (Convert.ToDouble(ds, geMean))
        (Convert.ToDouble(ds, median))
    fmt "ToInt16"
        (Convert.ToInt16(ds, null))
        (Convert.ToInt16(ds, geMean))
        (Convert.ToInt16(ds, median))
    fmt "ToInt32"
        (Convert.ToInt32(ds, null))
        (Convert.ToInt32(ds, geMean))
        (Convert.ToInt32(ds, median))
    fmt "ToInt64"
        (Convert.ToInt64(ds, null))
        (Convert.ToInt64(ds, geMean))
        (Convert.ToInt64(ds, median))
    fmt "ToSByte"
        (Convert.ToSByte(ds, null))
        (Convert.ToSByte(ds, geMean))
        (Convert.ToSByte(ds, median))
    fmt "ToSingle"
        (Convert.ToSingle(ds, null))
        (Convert.ToSingle(ds, geMean))
        (Convert.ToSingle(ds, median))
    fmt "ToUInt16"
        (Convert.ToUInt16(ds, null))
        (Convert.ToUInt16(ds, geMean))
        (Convert.ToUInt16(ds, median))
    fmt "ToUInt32"
        (Convert.ToUInt32(ds, null))
        (Convert.ToUInt32(ds, geMean))
        (Convert.ToUInt32(ds, median))
    fmt "ToUInt64"
        (Convert.ToUInt64(ds, null))
        (Convert.ToUInt64(ds, geMean))
        (Convert.ToUInt64(ds, median))

printfn
    """This example of the Convert.To<Type>( object, IFormatprovider) methods 
generates the following output. The example displays the values 
returned by the methods, using several IFormatProvider objects.
"""

let ds1 = DataSet(10.5, 22.2, 45.9, 88.7, 156.05, 297.6)
displayDataSet ds1

let ds2 = DataSet(359999.95, 425000, 499999.5, 775000, 1695000)
displayDataSet ds2

// This example of the Convert.To<Type>( object, IFormatprovider) methods
// generates the following output. The example displays the values
// returned by the methods, using several IFormatProvider objects.
//
// DataSet: [10.5, 22.2, 45.9, 88.7, 156.05, 297.6]
//
// Convert.                 Default      Geometric Mean              Median
// --------                 -------      --------------              ------
// ToBoolean                   True                True                True
// ToByte                       103                  59                  67
// ToChar                         g                   ;                   C
// ToDateTime   2003-05-13 15:04:12 2003-05-13 15:03:28 2003-05-13 15:03:35
// ToDecimal       103.491666666667    59.4332135445164                67.3
// ToDouble        103.491666666667    59.4332135445164                67.3
// ToInt16                      103                  59                  67
// ToInt32                      103                  59                  67
// ToInt64                      103                  59                  67
// ToSByte                      103                  59                  67
// ToSingle                103.4917            59.43321                67.3
// ToUInt16                     103                  59                  67
// ToUInt32                     103                  59                  67
// ToUInt64                     103                  59                  67
//
// DataSet: [359999.95, 425000, 499999.5, 775000, 1695000]
//
// Convert.                 Default      Geometric Mean              Median
// --------                 -------      --------------              ------
// ToBoolean                   True                True                True
// ToByte                       255                 255                 255
// ToChar                         ?                   ?                   ?
// ToDateTime   2003-05-22 07:39:08 2003-05-20 22:28:45 2003-05-19 09:55:48
// ToDecimal              750999.89    631577.237188435            499999.5
// ToDouble               750999.89    631577.237188435            499999.5
// ToInt16                    32767               32767               32767
// ToInt32                   751000              631577              500000
// ToInt64                   751000              631577              500000
// ToSByte                      127                 127                 127
// ToSingle                750999.9            631577.3            499999.5
// ToUInt16                   65535               65535               65535
// ToUInt32                  751000              631577              500000
// ToUInt64                  751000              631577              500000

Imports System.Collections

Module IConvertibleProviderDemo

    ' Define the types of averaging available in the class 
    ' implementing IConvertible.
    Enum AverageType as Short
        None = 0
        GeometricMean = 1
        ArithmeticMean = 2
        Median = 3
    End Enum

    ' Pass an instance of this class to methods that require an 
    ' IFormatProvider. The class instance determines the type of 
    ' average to calculate.
    Public Class AverageInfo
        Implements IFormatProvider

        Protected  AvgType      As AverageType

        ' Specify the type of averaging in the constructor.
        Public Sub New( avgType As AverageType )
            Me.AvgType = avgType
        End Sub

        ' This method returns a reference to the containing object 
        ' if an object of AverageInfo type is requested. 
        Public Function GetFormat( argType As Type ) As Object _
            Implements IFormatProvider.GetFormat

            If argType Is GetType( AverageInfo ) Then
                Return Me
            Else
                Return Nothing
            End If
        End Function 

        ' Use this property to set or get the type of averaging.
        Public Property TypeOfAverage( ) As AverageType
            Get
                Return Me.AvgType
            End Get
            Set( ByVal value as AverageType )
                Me.AvgType = value
            End Set
        End Property
    End Class 

    ' This class encapsulates an array of Double values and implements 
    ' the IConvertible interface. Most of the IConvertible methods 
    ' return an average of the array elements in one of three types: 
    ' arithmetic mean, geometric mean, or median. 
    Public Class DataSet
        Implements IConvertible

        Protected data              As ArrayList
        Protected defaultProvider   As AverageInfo
           
        ' Construct the object and add an initial list of values.
        ' Create a default format provider.
        Public Sub New( ParamArray values( ) As Double )
            data = New ArrayList( values )
            defaultProvider = New AverageInfo( _
                AverageType.ArithmeticMean )  
        End Sub
           
        ' Add additional values with this method.
        Public Function Add( value As Double ) As Integer
            data.Add( value )
            Return data.Count
        End Function
           
        ' Get, set, and add values with this indexer property.
        Default Public Property Item(index As Integer) As Double
            Get
                If index >= 0 AndAlso index < data.Count Then
                    Return System.Convert.ToDouble( data( index ) )
                Else
                    Throw New InvalidOperationException( _
                        "[DataSet.get] Index out of range." )
                End If
            End Get
            Set
                If index >= 0 AndAlso index < data.Count Then
                    data( index ) = value
                 
                ElseIf index = data.Count Then
                    data.Add( value )
                Else
                    Throw New InvalidOperationException( _
                        "[DataSet.set] Index out of range." )
                End If
            End Set
        End Property
          
        ' This property returns the number of elements in the object.
        Public ReadOnly Property Count( ) As Integer
            Get
                Return data.Count
            End Get
        End Property

        ' This method calculates the average of the object's elements.
        Protected Function Average( ByVal avgType As AverageType ) As Double

            Dim SumProd As Double 
            Dim Index   As Integer

            If data.Count = 0 Then Return 0.0

            Select Case avgType
                
                Case AverageType.GeometricMean

                    SumProd = 1.0
                    For Index = 0 To data.Count - 1
                        SumProd *= data( Index )
                    Next Index
                    
                    ' This calculation will not fail with negative 
                    ' elements.
                    Return Math.Sign( SumProd ) * Math.Pow( _
                        Math.Abs( SumProd ), 1.0 / data.Count )

                Case AverageType.ArithmeticMean

                    SumProd = 0.0
                    For Index = 0 To data.Count - 1
                        SumProd += data( Index )
                    Next Index

                    Return SumProd / data.Count 

                Case AverageType.Median

                    If data.Count Mod 2 = 0 Then
                        Return ( data( data.Count \ 2 ) + _
                            data( data.Count \ 2 - 1 ) ) / 2.0
                    Else
                        Return data( data.Count \ 2 ) 
                    End If
            End Select
        End Function

        ' Get the AverageInfo object from the caller's format 
        ' provider, or use the local default.
        Protected Function GetAverageInfo( _
            provider As IFormatProvider ) As AverageInfo

            Dim avgInfo As AverageInfo = Nothing

            If Not provider Is Nothing Then
                avgInfo = provider.GetFormat( GetType( AverageInfo ) )
            End If

            Return IIf( avgInfo Is Nothing, defaultProvider, avgInfo )
            
        End Function           

        ' Calculate the average and limit the range.
        Protected Function CalcNLimitAverage( min As Double, _
            max As Double, provider as IFormatProvider ) As Double

            ' Get the format provider and calculate the average.
            Dim avgInfo As AverageInfo = GetAverageInfo( provider )
            Dim avg As Double = Average( avgInfo.TypeOfAverage )

            ' Limit the range, based on the minimum and maximum values 
            ' for the type.
            Return IIf( avg > max, max, IIf( avg < min, min, avg ) )

        End Function

        ' The following elements are required by IConvertible.

        ' None of these conversion functions throw exceptions. When
        ' the data is out of range for the type, the appropriate
        ' MinValue or MaxValue is used.
        Public Function GetTypeCode( ) As TypeCode _
            Implements IConvertible.GetTypeCode
            Return TypeCode.Object
        End Function

        Function ToBoolean( ByVal provider As IFormatProvider ) As _
            Boolean Implements IConvertible.ToBoolean

            ' ToBoolean is false if the dataset is empty.
            If data.Count <= 0 Then
                Return False

            ' For median averaging, ToBoolean is true if any 
            ' non-discarded elements are nonzero.
            ElseIf AverageType.Median = _
                GetAverageInfo( provider ).TypeOfAverage Then

                If data.Count Mod 2 = 0 Then
                    Return ( data( data.Count \ 2 ) <> 0.0 Or _
                        data( data.Count \ 2 - 1 ) <> 0.0 )
                Else
                    Return data( data.Count \ 2 ) <> 0.0
                End If

            ' For arithmetic or geometric mean averaging, ToBoolean is 
            ' true if any element of the dataset is nonzero.  
            Else
                Dim Index As Integer
                For Index = 0 To data.Count - 1
                    If data( Index ) <> 0.0 Then Return True
                Next Index
                Return False
            End If
        End Function

        Function ToByte( ByVal provider As IFormatProvider ) As Byte _
            Implements IConvertible.ToByte
            Return Convert.ToByte( CalcNLimitAverage( _
                Byte.MinValue, Byte.MaxValue, provider ) )
        End Function

        Function ToChar( ByVal provider As IFormatProvider ) As Char _
            Implements IConvertible.ToChar
            Return Convert.ToChar( Convert.ToUInt16( _
                CalcNLimitAverage( 0.0, &HFFFF, provider ) ) )
        End Function

        ' Convert to DateTime by adding the calculated average as 
        ' seconds to the current date and time. A valid DateTime is 
        ' always returned.
        Function ToDateTime( ByVal provider As IFormatProvider ) As _
            DateTime Implements IConvertible.ToDateTime
            Dim seconds As Double = Average( _
                GetAverageInfo( provider ).TypeOfAverage )
            Try
                Return DateTime.Now.AddSeconds( seconds )
            Catch ex As ArgumentOutOfRangeException 
                Return IIf( seconds < 0.0, DateTime.MinValue, _
                    DateTime.MaxValue )
            End Try
        End Function

        Function ToDecimal( ByVal provider As IFormatProvider ) As _
            Decimal Implements IConvertible.ToDecimal

            ' The Double conversion rounds Decimal.MinValue and
            ' Decimal.MaxValue to invalid Decimal values, so the 
            ' following limits must be used.
            Return Convert.ToDecimal( CalcNLimitAverage( _
                -79228162514264330000000000000.0, _
                79228162514264330000000000000.0, provider ) )
        End Function

        Function ToDouble( ByVal provider As IFormatProvider) As _
            Double Implements IConvertible.ToDouble
            Return Average( GetAverageInfo( provider ).TypeOfAverage )
        End Function

        Function ToInt16( ByVal provider As IFormatProvider ) As _
            Short Implements IConvertible.ToInt16
            Return Convert.ToInt16( CalcNLimitAverage( _
                Int16.MinValue, Int16.MaxValue, provider ) )
        End Function

        Function ToInt32( ByVal provider As IFormatProvider ) As _
            Integer Implements IConvertible.ToInt32
            Return Convert.ToInt32( CalcNLimitAverage( _
                Int32.MinValue, Int32.MaxValue, provider ) )
        End Function

        Function ToInt64( ByVal provider As IFormatProvider ) As Long _
            Implements IConvertible.ToInt64

            ' The Double conversion rounds Int64.MinValue and 
            ' Int64.MaxValue to invalid Long values, so the following 
            ' limits must be used.
            Return Convert.ToInt64( CalcNLimitAverage( _
                -9223372036854775000, 9223372036854775000, provider ) )
        End Function

        Function ToSByte( ByVal provider As IFormatProvider ) As _
            SByte Implements IConvertible.ToSByte

            ' SByte.MinValue and SByte.MaxValue are not defined in
            ' Visual Basic.
            Return Convert.ToSByte( CalcNLimitAverage( _
                -128, 127, provider ) )
        End Function

        Function ToSingle( ByVal provider As IFormatProvider ) As _
            Single Implements IConvertible.ToSingle
            Return Convert.ToSingle( CalcNLimitAverage( _
                Single.MinValue, Single.MaxValue, provider ) )
        End Function

        Function ToUInt16( ByVal provider As IFormatProvider ) As _
            UInt16 Implements IConvertible.ToUInt16

            ' UInt16.MinValue and UInt16.MaxValue are not defined in 
            ' Visual Basic.
            Return Convert.ToUInt16( CalcNLimitAverage( _
                0, &HFFFF, provider ) )
        End Function

        Function ToUInt32( ByVal provider As IFormatProvider ) As _
            UInt32 Implements IConvertible.ToUInt32

            ' UInt32.MinValue and UInt32.MaxValue are not defined in 
            ' Visual Basic.
            Return Convert.ToUInt32( CalcNLimitAverage( _
                0, 4294967295, provider ) )
        End Function

        Function ToUInt64( ByVal provider As IFormatProvider ) As _
            UInt64 Implements IConvertible.ToUInt64

            ' UInt64.MinValue and UInt64.MaxValue are not defined in 
            ' Visual Basic. The Double conversion would have rounded 
            ' UInt64.MaxValue, so the following limit must be used.
            Return Convert.ToUInt64( CalcNLimitAverage( _
                0, 18446744073709550000.0, provider ) )
        End Function

        Function ToType( ByVal conversionType As Type, _
            ByVal provider As IFormatProvider) As Object _
            Implements IConvertible.ToType
            Return Convert.ChangeType( Average( GetAverageInfo( _
                provider ).TypeOfAverage ), conversionType )
        End Function

        Overloads Function ToString( ByVal provider As IFormatProvider _
            ) As String Implements IConvertible.ToString
            Dim avgType as AverageType = _
                GetAverageInfo( provider ).TypeOfAverage
            Return String.Format( "( {0}: {1:G10} )", avgType, _
                Average( avgType ) )
        End Function
    End Class
   
    ' Display a DataSet with three different format providers.
    Sub DisplayDataSet( ds As DataSet )

        Dim fmt    As String      = "{0,-12}{1,20}{2,20}{3,20}"
        Dim median As AverageInfo = New AverageInfo( AverageType.Median )
        Dim geMean As AverageInfo = _
            New AverageInfo( AverageType.GeometricMean )
        Dim iX     As Integer

        ' Display the dataset elements.
        If ds.Count > 0 Then
            Console.Write( vbCrLf & "DataSet: [{0}", ds( 0 ) )
            For iX = 1 To ds.Count - 1
                Console.Write( ", {0}", ds( iX ) )
            Next iX
            Console.WriteLine( "]" & vbCrLf )
        End If

        Console.WriteLine( fmt, "Convert.", "Default", _
            "Geometric Mean", "Median" )
        Console.WriteLine( fmt, "--------", "-------", _
            "--------------", "------" )
        Console.WriteLine( fmt, "ToBoolean", _
            Convert.ToBoolean( ds, Nothing ), _
            Convert.ToBoolean( ds, geMean ), _
            Convert.ToBoolean( ds, median ) )
        Console.WriteLine( fmt, "ToByte", _
            Convert.ToByte( ds, Nothing ), _
            Convert.ToByte( ds, geMean ), _
            Convert.ToByte( ds, median ) )
        Console.WriteLine( fmt, "ToChar", _
            Convert.ToChar( ds, Nothing ), _
            Convert.ToChar( ds, geMean ), _
            Convert.ToChar( ds, median ) )
        Console.WriteLine( "{0,-12}{1,20:yyyy-MM-dd HH:mm:ss}" & _
            "{2,20:yyyy-MM-dd HH:mm:ss}{3,20:yyyy-MM-dd HH:mm:ss}", _
            "ToDateTime", Convert.ToDateTime( ds, Nothing ), _
            Convert.ToDateTime( ds, geMean ), _
            Convert.ToDateTime( ds, median ) )
        Console.WriteLine( fmt, "ToDecimal", _
            Convert.ToDecimal( ds, Nothing ), _
            Convert.ToDecimal( ds, geMean ), _
            Convert.ToDecimal( ds, median ) )
        Console.WriteLine( fmt, "ToDouble", _
            Convert.ToDouble( ds, Nothing ), _
            Convert.ToDouble( ds, geMean ), _
            Convert.ToDouble( ds, median ) )
        Console.WriteLine( fmt, "ToInt16", _
            Convert.ToInt16( ds, Nothing ), _
            Convert.ToInt16( ds, geMean ), _
            Convert.ToInt16( ds, median ) )
        Console.WriteLine( fmt, "ToInt32", _
            Convert.ToInt32( ds, Nothing ), _
            Convert.ToInt32( ds, geMean ), _
            Convert.ToInt32( ds, median ) )
        Console.WriteLine( fmt, "ToInt64", _
            Convert.ToInt64( ds, Nothing ), _
            Convert.ToInt64( ds, geMean ), _
            Convert.ToInt64( ds, median ) )
        Console.WriteLine( fmt, "ToSByte", _
            Convert.ToSByte( ds, Nothing ), _
            Convert.ToSByte( ds, geMean ), _
            Convert.ToSByte( ds, median ) )
        Console.WriteLine( fmt, "ToSingle", _
            Convert.ToSingle( ds, Nothing ), _
            Convert.ToSingle( ds, geMean ), _
            Convert.ToSingle( ds, median ) )
        Console.WriteLine( fmt, "ToUInt16", _
            Convert.ToUInt16( ds, Nothing ), _
            Convert.ToUInt16( ds, geMean ), _
            Convert.ToUInt16( ds, median ) )
        Console.WriteLine( fmt, "ToUInt32", _
            Convert.ToUInt32( ds, Nothing ), _
            Convert.ToUInt32( ds, geMean ), _
            Convert.ToUInt32( ds, median ) )
        Console.WriteLine( fmt, "ToUInt64", _
            Convert.ToUInt64( ds, Nothing ), _
            Convert.ToUInt64( ds, geMean ), _
            Convert.ToUInt64( ds, median ) )
    End Sub
   
    Sub Main( )
        Console.WriteLine( _
            "This example of the Convert.To<Type>( Object, " & _
            "IFormatProvider ) methods " & vbCrLf & "generates " & _
            "the following output. The example displays the " & _
            "values " & vbCrLf & "returned by the methods, " & _
            "using several IFormatProvider objects." & vbCrLf )
          
        Dim ds1 As New DataSet( 10.5, 22.2, 45.9, 88.7, 156.05, 297.6 )
        DisplayDataSet( ds1 )
          
        Dim ds2 As New DataSet( _
            359999.95, 425000, 499999.5, 775000, 1695000 )
        DisplayDataSet( ds2 )
    End Sub 
End Module 

' This example of the Convert.To<Type>( Object, IFormatProvider ) methods
' generates the following output. The example displays the values
' returned by the methods, using several IFormatProvider objects.
' 
' DataSet: [10.5, 22.2, 45.9, 88.7, 156.05, 297.6]
' 
' Convert.                 Default      Geometric Mean              Median
' --------                 -------      --------------              ------
' ToBoolean                   True                True                True
' ToByte                       103                  59                  67
' ToChar                         g                   ;                   C
' ToDateTime   2003-05-13 14:52:53 2003-05-13 14:52:09 2003-05-13 14:52:17
' ToDecimal       103.491666666667    59.4332135445164                67.3
' ToDouble        103.491666666667    59.4332135445164                67.3
' ToInt16                      103                  59                  67
' ToInt32                      103                  59                  67
' ToInt64                      103                  59                  67
' ToSByte                      103                  59                  67
' ToSingle                103.4917            59.43321                67.3
' ToUInt16                     103                  59                  67
' ToUInt32                     103                  59                  67
' ToUInt64                     103                  59                  67
' 
' DataSet: [359999.95, 425000, 499999.5, 775000, 1695000]
' 
' Convert.                 Default      Geometric Mean              Median
' --------                 -------      --------------              ------
' ToBoolean                   True                True                True
' ToByte                       255                 255                 255
' ToChar                         ?                   ?                   ?
' ToDateTime   2003-05-22 07:27:49 2003-05-20 22:17:27 2003-05-19 09:44:29
' ToDecimal              750999.89    631577.237188435            499999.5
' ToDouble               750999.89    631577.237188435            499999.5
' ToInt16                    32767               32767               32767
' ToInt32                   751000              631577              500000
' ToInt64                   751000              631577              500000
' ToSByte                      127                 127                 127
' ToSingle                750999.9            631577.3            499999.5
' ToUInt16                   65535               65535               65535
' ToUInt32                  751000              631577              500000
' ToUInt64                  751000              631577              500000

注釈

戻り値は、 の基になる型valueの IConvertible.ToInt32 メソッドを呼び出した結果です。

provider を使用すると、ユーザーは のコンテンツに関するカルチャ固有の value変換情報を指定できます。 たとえば、 が数値をString表す の場合valueは、providerその数値を表すために使用される表記に関するカルチャ固有の情報を提供できます。

基本型は無視 providerします。ただし、 が インターフェイスを実装するユーザー定義型の場合 value は、 パラメーターを IConvertible 使用できます。

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(System::String ^ value, IFormatProvider ^ provider);

public static int ToInt32 (string value, IFormatProvider provider);

public static int ToInt32 (string? value, IFormatProvider? provider);

static member ToInt32 : string * IFormatProvider -> int

Public Shared Function ToInt32 (value As String, provider As IFormatProvider) As Integer

パラメーター

戻り値

value の数値と等価の 32 ビット符号付き整数。value が null の場合は 0 (ゼロ)。

例外

例

次の例では、文字列 "pos" を正の符号として認識し、文字列 "neg" を負の符号として認識するカスタム NumberFormatInfo オブジェクトを定義します。 次に、このプロバイダーとインバリアント カルチャのプロバイダーの両方を使用して、数値文字列配列の各要素を NumberFormatInfo 整数に変換しようとします。

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      // Create a custom NumberFormatInfo object and set its two properties
      // used by default in parsing numeric strings.
      NumberFormatInfo customProvider = new NumberFormatInfo();
      customProvider.NegativeSign = "neg ";
      customProvider.PositiveSign = "pos ";

      // Add custom and invariant provider to an array of providers.
      NumberFormatInfo[] providers = { customProvider, NumberFormatInfo.InvariantInfo };

      // Define an array of strings to convert.
      string[] numericStrings = { "123456789", "+123456789", "pos 123456789",
                                  "-123456789", "neg 123456789", "123456789.",
                                  "123,456,789", "(123456789)", "2147483648",
                                  "-2147483649" };

      // Use each provider to parse all the numeric strings.
      for (int ctr = 0; ctr <= 1; ctr++)
      {
         IFormatProvider provider = providers[ctr];
         Console.WriteLine(ctr == 0 ? "Custom Provider:" : "Invariant Provider:");
         foreach (string numericString in numericStrings)
         {
            Console.Write("{0,15}  --> ", numericString);
            try {
               Console.WriteLine("{0,20}", Convert.ToInt32(numericString, provider));
            }
            catch (FormatException) {
               Console.WriteLine("{0,20}", "FormatException");
            }
            catch (OverflowException) {
               Console.WriteLine("{0,20}", "OverflowException");
            }
         }
         Console.WriteLine();
      }
   }
}
// The example displays the following output:
//       Custom Provider:
//             123456789  -->            123456789
//            +123456789  -->      FormatException
//         pos 123456789  -->            123456789
//            -123456789  -->      FormatException
//         neg 123456789  -->           -123456789
//            123456789.  -->      FormatException
//           123,456,789  -->      FormatException
//           (123456789)  -->      FormatException
//            2147483648  -->    OverflowException
//           -2147483649  -->      FormatException
//
//       Invariant Provider:
//             123456789  -->            123456789
//            +123456789  -->            123456789
//         pos 123456789  -->      FormatException
//            -123456789  -->           -123456789
//         neg 123456789  -->      FormatException
//            123456789.  -->      FormatException
//           123,456,789  -->      FormatException
//           (123456789)  -->      FormatException
//            2147483648  -->    OverflowException
//           -2147483649  -->    OverflowException

open System
open System.Globalization

// Create a custom NumberFormatInfo object and set its two properties
// used by default in parsing numeric strings.
let customProvider = NumberFormatInfo()
customProvider.NegativeSign <- "neg "
customProvider.PositiveSign <- "pos "

// Add custom and invariant provider to an array of providers.
let providers =
    [| customProvider; NumberFormatInfo.InvariantInfo |]

// Define an array of strings to convert.
let numericStrings =
    [| "123456789"; "+123456789"; "pos 123456789"
       "-123456789"; "neg 123456789"; "123456789."
       "123,456,789"; "(123456789)"; "2147483648"
       "-2147483649"; |]

// Use each provider to parse all the numeric strings.
for i = 0 to 1 do
    let provider = providers[i]
    printfn $"""{if i = 0 then "Custom Provider:" else "Invariant Provider:"}"""
    for numericString in numericStrings do
        printf $"{numericString,15}  --> "
        try
            printfn $"{Convert.ToInt32(numericString, provider),20}"
        with
        | :? FormatException ->
            printfn "%20s" "FormatException"
        | :? OverflowException ->
            printfn "%20s" "OverflowException"
    printfn ""
// The example displays the following output:
//       Custom Provider:
//             123456789  -->            123456789
//            +123456789  -->      FormatException
//         pos 123456789  -->            123456789
//            -123456789  -->      FormatException
//         neg 123456789  -->           -123456789
//            123456789.  -->      FormatException
//           123,456,789  -->      FormatException
//           (123456789)  -->      FormatException
//            2147483648  -->    OverflowException
//           -2147483649  -->      FormatException
//
//       Invariant Provider:
//             123456789  -->            123456789
//            +123456789  -->            123456789
//         pos 123456789  -->      FormatException
//            -123456789  -->           -123456789
//         neg 123456789  -->      FormatException
//            123456789.  -->      FormatException
//           123,456,789  -->      FormatException
//           (123456789)  -->      FormatException
//            2147483648  -->    OverflowException
//           -2147483649  -->    OverflowException

Imports System.Globalization

Module Example
   Public Sub Main()
      ' Create a custom NumberFormatInfo object and set its two properties
      ' used by default in parsing numeric strings.
      Dim customProvider As New NumberFormatInfo()
      customProvider.NegativeSign = "neg "
      customProvider.PositiveSign = "pos "

      ' Add custom and invariant provider to an array of providers.
      Dim providers() As NumberFormatInfo = { customProvider, NumberFormatInfo.InvariantInfo }
      
      ' Define an array of strings to convert.
      Dim numericStrings() As String = { "123456789", "+123456789", "pos 123456789", _
                                         "-123456789", "neg 123456789", "123456789.", _
                                         "123,456,789", "(123456789)", "2147483648", _
                                         "-2147483649" } 
      
      ' Use each provider to parse all the numeric strings.
      For ctr As Integer = 0 To 1
         Dim provider As IFormatPRovider = providers(ctr)
         Console.WriteLine(IIf(ctr = 0, "Custom Provider:", "Invariant Provider:"))
         For Each numericString As String In numericStrings
            Console.Write("{0,15}  --> ", numericString)
            Try
               Console.WriteLine("{0,20}", Convert.ToInt32(numericString, provider))
            Catch e As FormatException
               Console.WriteLine("{0,20}", "FormatException") 
            Catch e As OverflowException
               Console.WriteLine("{0,20}", "OverflowException")                 
            End Try
         Next
         Console.WriteLine()
      Next                  
   End Sub 
End Module 
' The example displays the following output:
'       Custom Provider:
'             123456789  -->            123456789
'            +123456789  -->      FormatException
'         pos 123456789  -->            123456789
'            -123456789  -->      FormatException
'         neg 123456789  -->           -123456789
'            123456789.  -->      FormatException
'           123,456,789  -->      FormatException
'           (123456789)  -->      FormatException
'            2147483648  -->    OverflowException
'           -2147483649  -->      FormatException
'       
'       Invariant Provider:
'             123456789  -->            123456789
'            +123456789  -->            123456789
'         pos 123456789  -->      FormatException
'            -123456789  -->           -123456789
'         neg 123456789  -->      FormatException
'            123456789.  -->      FormatException
'           123,456,789  -->      FormatException
'           (123456789)  -->      FormatException
'            2147483648  -->    OverflowException
'           -2147483649  -->    OverflowException

注釈

戻り値は、 で valueメソッドを呼び出したInt32.Parse結果です。

provider は、 オブジェクトを IFormatProvider 取得するインスタンスです NumberFormatInfo 。 オブジェクトは NumberFormatInfo 、 の形式に関するカルチャ固有の value情報を提供します。 が のnull場合providerは、NumberFormatInfo現在のカルチャの が使用されます。

変換が失敗した場合に例外を処理しない場合は、代わりに メソッドを Int32.TryParse 呼び出すことができます。 変換が Boolean 成功したか失敗したかを示す値を返します。

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(System::String ^ value, int fromBase);

public static int ToInt32 (string value, int fromBase);

public static int ToInt32 (string? value, int fromBase);

static member ToInt32 : string * int -> int

Public Shared Function ToInt32 (value As String, fromBase As Integer) As Integer

パラメーター

戻り値

value の数値と等価の 32 ビット符号付き整数。value が null の場合は 0 (ゼロ)。

例外

注釈

が 16 の場合 fromBase は、パラメーターで指定された数値の前に value "0x" または "0X" を付けることができます。

負の符号は 10 の数値以外の表現ではサポートされていないため、 メソッドは負の ToInt32(String, Int32) 数値が 2 の補数表現を使用することを前提としています。 つまり、 メソッドは常に、整数 (ビット 31) の最上位バイナリ ビットを符号ビットとして解釈します。 その結果、データ型の範囲外 Int32 の 10 以外の数値が、メソッドが例外をスローせずに値に Int32 変換されるコードを記述できます。 次の例では、1 ずつインクリメント Int32.MaxValue し、結果の数値を 16 進数の文字列表現に変換してから、 メソッドを ToInt32(String, Int32) 呼び出します。 メソッドは例外をスローする代わりに、"0x80000000 -2147483648 に変換します" というメッセージを表示します。

// Create a hexadecimal value out of range of the integer type. 
String^ value1 = Convert::ToString((static_cast<__int64>(int::MaxValue)) + 1, 16);
// Convert it back to a number.
try {
   int number = Convert::ToInt32(value1, 16);
   Console::WriteLine("0x{0} converts to {1}.", value1, number);
}
catch (OverflowException ^e) {
   Console::WriteLine("Unable to convert '0x{0}' to an integer.", value1);
}
// The example displays the following output:
//      0x80000000 converts to -2147483648.

// Create a hexadecimal value out of range of the Integer type.
string value = Convert.ToString((long) int.MaxValue + 1, 16);
// Convert it back to a number.
try
{
   int number = Convert.ToInt32(value, 16);
   Console.WriteLine("0x{0} converts to {1}.", value, number.ToString());
}
catch (OverflowException)
{
   Console.WriteLine("Unable to convert '0x{0}' to an integer.", value);
}

// Create a hexadecimal value out of range of the Integer type.
let value = Convert.ToString(int64 Int32.MaxValue + 1L, 16)
// Convert it back to a number.
try
    let number = Convert.ToInt32(value, 16)
    printfn $"0x{value} converts to {number}."
with :? OverflowException ->
    printfn $"Unable to convert '0x{value}' to an integer."

' Create a hexadecimal value out of range of the Integer type.
Dim value As String = Convert.ToString(CLng(Integer.MaxValue) + 1, 16)
' Convert it back to a number.
Try
   Dim number As Integer = Convert.ToInt32(value, 16)
   Console.WriteLine("0x{0} converts to {1}.", value, number)
Catch e As OverflowException
   Console.WriteLine("Unable to convert '0x{0}' to an integer.", value)
End Try

バイナリ演算または数値変換を実行するときは、常に開発者が、メソッドが適切な数値表現を使用して特定の値を解釈していることを確認する必要があります。 次の例に示すように、数値の符号を取得してから 16 進数の文字列表現に変換することで、メソッドが適切にオーバーフローを処理するようにすることができます。 元の値が正の場合は例外をスローしますが、整数に戻すと負の値が返されます。

__int64 sourceNumber2 = (static_cast<__int64>(int::MaxValue)) + 1;
bool isNegative = Math::Sign(sourceNumber2) == -1;
String^ value2 = Convert::ToString(sourceNumber2, 16);
int targetNumber;
try {
   targetNumber = Convert::ToInt32(value2, 16);
   if (!(isNegative) & (targetNumber & 0x80000000) != 0)
      throw gcnew OverflowException();
   else
      Console::WriteLine("0x{0} converts to {1}.", value2, targetNumber);
}
catch (OverflowException ^e) {
   Console::WriteLine("Unable to convert '0x{0}' to an integer.", value2);
}
// The example displays the following output:
//       Unable to convert '0x80000000' to an integer.

// Create a hexadecimal value out of range of the Integer type.
long sourceNumber = (long) int.MaxValue + 1;
bool isNegative = Math.Sign(sourceNumber) == -1;
string value = Convert.ToString(sourceNumber, 16);
int targetNumber;
try
{
   targetNumber = Convert.ToInt32(value, 16);
   if (!(isNegative) & (targetNumber & 0x80000000) != 0)
      throw new OverflowException();
   else
      Console.WriteLine("0x{0} converts to {1}.", value, targetNumber);
}
catch (OverflowException)
{
   Console.WriteLine("Unable to convert '0x{0}' to an integer.", value);
}
// Displays the following to the console:
//    Unable to convert '0x80000000' to an integer.

// Create a hexadecimal value out of range of the Integer type.
let sourceNumber = int64 Int32.MaxValue + 1L
let isNegative = sign sourceNumber = -1
let value = Convert.ToString(sourceNumber, 16)
try
    let targetNumber = Convert.ToInt32(value, 16)
    if not isNegative && targetNumber &&& 0x80000000 <> 0 then
        raise (OverflowException())
    else
    printfn $"0x{value} converts to {targetNumber}."
with :? OverflowException ->
    printfn $"Unable to convert '0x{value}' to an integer."
// Displays the following to the console:
//    Unable to convert '0x80000000' to an integer.

' Create a hexadecimal value out of range of the Integer type.
Dim sourceNumber As Long = CLng(Integer.MaxValue) + 1
Dim isNegative As Boolean = (Math.Sign(sourceNumber) = -1)
Dim value As String = Convert.ToString(sourceNumber, 16)
Dim targetNumber As Integer
Try
   targetNumber = Convert.ToInt32(value, 16)
   If Not isNegative And ((targetNumber And &H80000000) <> 0) Then
      Throw New OverflowException()
   Else 
      Console.WriteLine("0x{0} converts to {1}.", value, targetNumber)
   End If    
Catch e As OverflowException
   Console.WriteLine("Unable to convert '0x{0}' to an integer.", value)
End Try 
' Displays the following to the console:
'    Unable to convert '0x80000000' to an integer.

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(System::UInt64 value);

[System.CLSCompliant(false)]
public static int ToInt32 (ulong value);

[<System.CLSCompliant(false)>]
static member ToInt32 : uint64 -> int

Public Shared Function ToInt32 (value As ULong) As Integer

パラメーター

戻り値

value と等価の 32 ビット符号付き整数。

属性

CLSCompliantAttribute

例外

例

次の例では、符号なし長整数の配列内の各要素を符号付き整数に変換しようとしています。

ulong[] numbers = { UInt64.MinValue, 121, 340, UInt64.MaxValue };
int result;
foreach (ulong number in numbers)
{
   try {
      result = Convert.ToInt32(number);
      Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    Converted the UInt64 value 0 to a Int32 value 0.
//    Converted the UInt64 value 121 to a Int32 value 121.
//    Converted the UInt64 value 340 to a Int32 value 340.
//    The UInt64 value 18446744073709551615 is outside the range of the Int32 type.

let numbers =
    [| UInt64.MinValue; 121uL; 340uL; UInt64.MaxValue |]

for number in numbers do
    try
        let result = Convert.ToInt32 number
        printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"The {number.GetType().Name} value {number} is outside the range of the Int32 type."
// The example displays the following output:
//    Converted the UInt64 value 0 to a Int32 value 0.
//    Converted the UInt64 value 121 to a Int32 value 121.
//    Converted the UInt64 value 340 to a Int32 value 340.
//    The UInt64 value 18446744073709551615 is outside the range of the Int32 type.

Dim numbers() As ULong = { UInt64.MinValue, 121, 340, UInt64.MaxValue }
Dim result As Integer
For Each number As ULong In numbers
   Try
      result = Convert.ToInt32(number)
      Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    Converted the UInt64 value 0 to a Int32 value 0.
'    Converted the UInt64 value 121 to a Int32 value 121.
'    Converted the UInt64 value 340 to a Int32 value 340.
'    The UInt64 value 18446744073709551615 is outside the range of the Int32 type.

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(System::SByte value);

[System.CLSCompliant(false)]
public static int ToInt32 (sbyte value);

[<System.CLSCompliant(false)>]
static member ToInt32 : sbyte -> int

Public Shared Function ToInt32 (value As SByte) As Integer

パラメーター

戻り値

value と等価の 8 ビット符号付き整数。

属性

CLSCompliantAttribute

例

次の例では、符号付きバイトの配列内の各要素を整数に変換します。

sbyte[] numbers = { SByte.MinValue, -1, 0, 10, SByte.MaxValue };
int result;

foreach (sbyte number in numbers)
{
   result = Convert.ToInt32(number);
   Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                     number.GetType().Name, number,
                     result.GetType().Name, result);
}
// The example displays the following output:
//       Converted the SByte value -128 to the Int32 value -128.
//       Converted the SByte value -1 to the Int32 value -1.
//       Converted the SByte value 0 to the Int32 value 0.
//       Converted the SByte value 10 to the Int32 value 10.
//       Converted the SByte value 127 to the Int32 value 127.

let numbers =
    [| SByte.MinValue; -1y; 0y; 10y; SByte.MaxValue |]

for number in numbers do
    let result = Convert.ToInt32 number
    printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."
// The example displays the following output:
//       Converted the SByte value -128 to the Int32 value -128.
//       Converted the SByte value -1 to the Int32 value -1.
//       Converted the SByte value 0 to the Int32 value 0.
//       Converted the SByte value 10 to the Int32 value 10.
//       Converted the SByte value 127 to the Int32 value 127.

Dim numbers() As SByte = { SByte.MinValue, -1, 0, 10, SByte.MaxValue }
Dim result As Integer

For Each number As SByte In numbers
   result = Convert.ToInt32(number)
   Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                     number.GetType().Name, number, _
                     result.GetType().Name, result)
Next
' The example displays the following output:
'       Converted the SByte value -128 to the Int32 value -128.
'       Converted the SByte value -1 to the Int32 value -1.
'       Converted the SByte value 0 to the Int32 value 0.
'       Converted the SByte value 10 to the Int32 value 10.
'       Converted the SByte value 127 to the Int32 value 127.

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(System::Object ^ value);

public static int ToInt32 (object value);

public static int ToInt32 (object? value);

static member ToInt32 : obj -> int

Public Shared Function ToInt32 (value As Object) As Integer

パラメーター

戻り値

value と等価の 32 ビット符号付き整数。value が null の場合は 0。

例外

例

次の例では、オブジェクト配列内の各要素を整数に変換しようとしています。

object[] values = { true, -12, 163, 935, 'x', new DateTime(2009, 5, 12),
                    "104", "103.0", "-1",
                    "1.00e2", "One", 1.00e2, 16.3e42};
int result;

foreach (object value in values)
{
   try {
      result = Convert.ToInt32(value);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        value.GetType().Name, value,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.",
                        value.GetType().Name, value);
   }
   catch (FormatException) {
      Console.WriteLine("The {0} value {1} is not in a recognizable format.",
                        value.GetType().Name, value);
   }
   catch (InvalidCastException) {
      Console.WriteLine("No conversion to an Int32 exists for the {0} value {1}.",
                        value.GetType().Name, value);
   }
}
// The example displays the following output:
//    Converted the Boolean value True to the Int32 value 1.
//    Converted the Int32 value -12 to the Int32 value -12.
//    Converted the Int32 value 163 to the Int32 value 163.
//    Converted the Int32 value 935 to the Int32 value 935.
//    Converted the Char value x to the Int32 value 120.
//    No conversion to an Int32 exists for the DateTime value 5/12/2009 12:00:00 AM.
//    Converted the String value 104 to the Int32 value 104.
//    The String value 103.0 is not in a recognizable format.
//    Converted the String value -1 to the Int32 value -1.
//    The String value 1.00e2 is not in a recognizable format.
//    The String value One is not in a recognizable format.
//    Converted the Double value 100 to the Int32 value 100.
//    The Double value 1.63E+43 is outside the range of the Int32 type.

let values: obj[] = 
    [| true; -12; 163; 935; 'x'; DateTime(2009, 5, 12)
       "104"; "103.0"; "-1"
       "1.00e2"; "One"; 1.00e2; 16.3e42 |]

for value in values do
    try
        let result = Convert.ToInt32 value
        printfn $"Converted the {value.GetType().Name} value {value} to the {result.GetType().Name} value {result}."
    with 
    | :? OverflowException ->
        printfn $"The {value.GetType().Name} value {value} is outside the range of the Int32 type."
    | :? FormatException ->
        printfn $"The {value.GetType().Name} value {value} is not in a recognizable format."
    | :? InvalidCastException ->
        printfn $"No conversion to an Int32 exists for the {value.GetType().Name} value {value}."
// The example displays the following output:
//    Converted the Boolean value True to the Int32 value 1.
//    Converted the Int32 value -12 to the Int32 value -12.
//    Converted the Int32 value 163 to the Int32 value 163.
//    Converted the Int32 value 935 to the Int32 value 935.
//    Converted the Char value x to the Int32 value 120.
//    No conversion to an Int32 exists for the DateTime value 5/12/2009 12:00:00 AM.
//    Converted the String value 104 to the Int32 value 104.
//    The String value 103.0 is not in a recognizable format.
//    Converted the String value -1 to the Int32 value -1.
//    The String value 1.00e2 is not in a recognizable format.
//    The String value One is not in a recognizable format.
//    Converted the Double value 100 to the Int32 value 100.
//    The Double value 1.63E+43 is outside the range of the Int32 type.

Dim values() As Object = { True, -12, 163, 935, "x"c, #5/12/2009#, _
                           "104", "103.0", "-1", _
                           "1.00e2", "One", 1.00e2, 16.3e42}
Dim result As Integer

For Each value As Object In values
   Try
      result = Convert.ToInt32(value)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        value.GetType().Name, value, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.", _
                        value.GetType().Name, value)
   Catch e As FormatException
      Console.WriteLine("The {0} value {1} is not in a recognizable format.", _
                        value.GetType().Name, value)
   Catch e As InvalidCastException
      Console.WriteLine("No conversion to an Int32 exists for the {0} value {1}.", _
                        value.GetType().Name, value)
                        
   End Try
Next                           
' The example displays the following output:
'    Converted the Boolean value True to the Int32 value 1.
'    Converted the Int32 value -12 to the Int32 value -12.
'    Converted the Int32 value 163 to the Int32 value 163.
'    Converted the Int32 value 935 to the Int32 value 935.
'    Converted the Char value x to the Int32 value 120.
'    No conversion to an Int32 exists for the DateTime value 5/12/2009 12:00:00 AM.
'    Converted the String value 104 to the Int32 value 104.
'    The String value 103.0 is not in a recognizable format.
'    Converted the String value -1 to the Int32 value -1.
'    The String value 1.00e2 is not in a recognizable format.
'    The String value One is not in a recognizable format.
'    Converted the Double value 100 to the Int32 value 100.
'    The Double value 1.63E+43 is outside the range of the Int32 type.

注釈

が でないnull場合value、このメソッドは、 の基になる型valueの実装のIConvertible.ToInt32呼び出しをラップします。

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(long value);

public static int ToInt32 (long value);

static member ToInt32 : int64 -> int

Public Shared Function ToInt32 (value As Long) As Integer

パラメーター

戻り値

value と等価の 32 ビット符号付き整数。

例外

例

次の例では、長整数の配列内の各要素を整数に変換しようとしています。

long[] numbers = { Int64.MinValue, -1, 0, 121, 340, Int64.MaxValue };
int result;
foreach (long number in numbers)
{
   try {
      result = Convert.ToInt32(number);
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.",
                        number.GetType().Name, number);
   }
}
// The example displays the following output:
//    The Int64 value -9223372036854775808 is outside the range of the Int32 type.
//    Converted the Int64 value -1 to the Int32 value -1.
//    Converted the Int64 value 0 to the Int32 value 0.
//    Converted the Int64 value 121 to the Int32 value 121.
//    Converted the Int64 value 340 to the Int32 value 340.
//    The Int64 value 9223372036854775807 is outside the range of the Int32 type.

let numbers =
    [| Int64.MinValue; -1; 0; 121; 340; Int64.MaxValue |]

for number in numbers do
    try
        let result = Convert.ToInt32 number
        printfn $"Converted the {number.GetType().Name} value {number} to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"The {number.GetType().Name} value {number} is outside the range of the Int32 type."
// The example displays the following output:
//    The Int64 value -9223372036854775808 is outside the range of the Int32 type.
//    Converted the Int64 value -1 to the Int32 value -1.
//    Converted the Int64 value 0 to the Int32 value 0.
//    Converted the Int64 value 121 to the Int32 value 121.
//    Converted the Int64 value 340 to the Int32 value 340.
//    The Int64 value 9223372036854775807 is outside the range of the Int32 type.

Dim numbers() As Long = { Int64.MinValue, -1, 0, 121, 340, Int64.MaxValue }
Dim result As Integer
For Each number As Long In numbers
   Try
      result = Convert.ToInt32(number)
      Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("The {0} value {1} is outside the range of the Int32 type.", _
                        number.GetType().Name, number)
   End Try
Next
' The example displays the following output:
'    The Int64 value -9223372036854775808 is outside the range of the Int32 type.
'    Converted the Int64 value -1 to the Int32 value -1.
'    Converted the Int64 value 0 to the Int32 value 0.
'    Converted the Int64 value 121 to the Int32 value 121.
'    Converted the Int64 value 340 to the Int32 value 340.
'    The Int64 value 9223372036854775807 is outside the range of the Int32 type.

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(System::Byte value);

public static int ToInt32 (byte value);

static member ToInt32 : byte -> int

Public Shared Function ToInt32 (value As Byte) As Integer

パラメーター

戻り値

value と等価の 32 ビット符号付き整数。

例

次の例では、バイト配列内の各要素を整数に変換します。

byte[] bytes = { Byte.MinValue, 14, 122, Byte.MaxValue};
int result;

foreach (byte byteValue in bytes)
{
   result = Convert.ToInt32(byteValue);
   Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.",
                     byteValue.GetType().Name, byteValue,
                     result.GetType().Name, result);
}
// The example displays the following output:
//       Converted the Byte value 0 to the Int32 value 0.
//       Converted the Byte value 14 to the Int32 value 14.
//       Converted the Byte value 122 to the Int32 value 122.
//       Converted the Byte value 255 to the Int32 value 255.

let bytes = 
    [| Byte.MinValue; 14uy; 122uy; Byte.MaxValue |]

for byteValue in bytes do
    let result = Convert.ToInt32 byteValue
    printfn $"Converted the {byteValue.GetType().Name} value {byteValue} to the {result.GetType().Name} value {result}."
// The example displays the following output:
//       Converted the Byte value 0 to the Int32 value 0.
//       Converted the Byte value 14 to the Int32 value 14.
//       Converted the Byte value 122 to the Int32 value 122.
//       Converted the Byte value 255 to the Int32 value 255.

Dim bytes() As Byte = { Byte.MinValue, 14, 122, Byte.MaxValue}
Dim result As Integer

For Each byteValue As Byte In bytes
   result = Convert.ToInt32(byteValue)
   Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                     byteValue.GetType().Name, byteValue, _
                     result.GetType().Name, result)
Next
' The example displays the following output:
'       Converted the Byte value 0 to the Int32 value 0.
'       Converted the Byte value 14 to the Int32 value 14.
'       Converted the Byte value 122 to the Int32 value 122.
'       Converted the Byte value 255 to the Int32 value 255.

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(char value);

public static int ToInt32 (char value);

static member ToInt32 : char -> int

Public Shared Function ToInt32 (value As Char) As Integer

パラメーター

戻り値

value と等価の 32 ビット符号付き整数。

例

次の例では、値の配列内の Char 各要素を整数に変換します。

char[] chars = { 'a', 'z', '\u0007', '\u03FF',
                 '\u7FFF', '\uFFFE' };
int result;

foreach (char ch in chars)
{
   try {
      result = Convert.ToInt32(ch);
      Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.",
                        ch.GetType().Name, ch,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("Unable to convert u+{0} to an Int32.",
                        ((int)ch).ToString("X4"));
   }
}
// The example displays the following output:
//       Converted the Char value 'a' to the Int32 value 97.
//       Converted the Char value 'z' to the Int32 value 122.
//       Converted the Char value '' to the Int32 value 7.
//       Converted the Char value 'Ͽ' to the Int32 value 1023.
//       Converted the Char value '翿' to the Int32 value 32767.
//       Converted the Char value '' to the Int32 value 65534.

let chars = 
    [| 'a'; 'z'; '\u0007'; '\u03FF'; '\u7FFF'; '\uFFFE' |]

for ch in chars do
    try
        let result = Convert.ToInt32 ch
        printfn $"Converted the {ch.GetType().Name} value '{ch}' to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"Unable to convert u+{int ch:X4} to an Int32."
// The example displays the following output:
//       Converted the Char value 'a' to the Int32 value 97.
//       Converted the Char value 'z' to the Int32 value 122.
//       Converted the Char value '' to the Int32 value 7.
//       Converted the Char value 'Ͽ' to the Int32 value 1023.
//       Converted the Char value '翿' to the Int32 value 32767.
//       Converted the Char value '' to the Int32 value 65534.

Dim chars() As Char = { "a"c, "z"c, ChrW(7), ChrW(1023), _
                        ChrW(Short.MaxValue), ChrW(&hFFFE) }
Dim result As Integer
                        
For Each ch As Char in chars
   Try
      result = Convert.ToInt32(ch)
      Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _
                        ch.GetType().Name, ch, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("Unable to convert u+{0} to an Int32.", _
                        AscW(ch).ToString("X4"))
   End Try
Next   
' The example displays the following output:
'       Converted the Char value 'a' to the Int32 value 97.
'       Converted the Char value 'z' to the Int32 value 122.
'       Converted the Char value '' to the Int32 value 7.
'       Converted the Char value 'Ͽ' to the Int32 value 1023.
'       Converted the Char value '翿' to the Int32 value 32767.
'       Converted the Char value '' to the Int32 value 65534.

注釈

メソッドは ToInt32(Char) 、引数の UTF-16 でエンコードされたコード単位を表す 32 ビット符号付き整数を value 返します。 が低サロゲートまたは上位サロゲートでない場合 value 、この戻り値は Unicode コードの値ポイントも表します。

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(DateTime value);

public static int ToInt32 (DateTime value);

static member ToInt32 : DateTime -> int

Public Shared Function ToInt32 (value As DateTime) As Integer

パラメーター

戻り値

この変換はサポートされていません。 値は返されません。

例外

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(bool value);

public static int ToInt32 (bool value);

static member ToInt32 : bool -> int

Public Shared Function ToInt32 (value As Boolean) As Integer

パラメーター

戻り値

value が true の場合は数値の 1。それ以外の場合は 0。

例

次の例では、 と false の値trueをBoolean整数に変換します。

bool falseFlag = false;
bool trueFlag = true;

Console.WriteLine("{0} converts to {1}.", falseFlag,
                  Convert.ToInt32(falseFlag));
Console.WriteLine("{0} converts to {1}.", trueFlag,
                  Convert.ToInt32(trueFlag));
// The example displays the following output:
//       False converts to 0.
//       True converts to 1.

let falseFlag = false
let trueFlag = true

printfn $"{falseFlag} converts to {Convert.ToInt32 falseFlag}."
printfn $"{trueFlag} converts to {Convert.ToInt32 trueFlag}."
// The example displays the following output:
//       False converts to 0.
//       True converts to 1.

Dim falseFlag As Boolean = False
Dim trueFlag As Boolean = True

Console.WriteLine("{0} converts to {1}.", falseFlag, _
                  Convert.ToInt32(falseFlag))
Console.WriteLine("{0} converts to {1}.", trueFlag, _
                  Convert.ToInt32(trueFlag))
' The example displays the following output:
'       False converts to 0.
'       True converts to 1.

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(double value);

public static int ToInt32 (double value);

static member ToInt32 : double -> int

Public Shared Function ToInt32 (value As Double) As Integer

パラメーター

戻り値

最も近い 32 ビット符号付き整数に丸められた value。 value が 2 つの整数のちょうど中間にある場合は、偶数が返されます。つまり、4.5 は 4 に変換され、5.5 は 6 に変換されます。

例外

例

次の例では、値の配列 Double 内の各要素を整数に変換しようとしています。

double[] values= { Double.MinValue, -1.38e10, -1023.299, -12.98,
                   0, 9.113e-16, 103.919, 17834.191, Double.MaxValue };
int result;

foreach (double value in values)
{
   try {
      result = Convert.ToInt32(value);
      Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.",
                        value.GetType().Name, value,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("{0} is outside the range of the Int32 type.", value);
   }
}
//    -1.79769313486232E+308 is outside the range of the Int32 type.
//    -13800000000 is outside the range of the Int32 type.
//    Converted the Double value '-1023.299' to the Int32 value -1023.
//    Converted the Double value '-12.98' to the Int32 value -13.
//    Converted the Double value '0' to the Int32 value 0.
//    Converted the Double value '9.113E-16' to the Int32 value 0.
//    Converted the Double value '103.919' to the Int32 value 104.
//    Converted the Double value '17834.191' to the Int32 value 17834.
//    1.79769313486232E+308 is outside the range of the Int32 type.

let values = 
    [| Double.MinValue; -1.38e10; -1023.299; -12.98
       0; 9.113e-16; 103.919; 17834.191; Double.MaxValue |]

for value in values do
    try
        let result = Convert.ToInt32 value
        printfn $"Converted the {value.GetType().Name} value '{value}' to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"{value} is outside the range of the Int32 type."
//    -1.79769313486232E+308 is outside the range of the Int32 type.
//    -13800000000 is outside the range of the Int32 type.
//    Converted the Double value '-1023.299' to the Int32 value -1023.
//    Converted the Double value '-12.98' to the Int32 value -13.
//    Converted the Double value '0' to the Int32 value 0.
//    Converted the Double value '9.113E-16' to the Int32 value 0.
//    Converted the Double value '103.919' to the Int32 value 104.
//    Converted the Double value '17834.191' to the Int32 value 17834.
//    1.79769313486232E+308 is outside the range of the Int32 type.

Dim values() As Double = { Double.MinValue, -1.38e10, -1023.299, -12.98, _
                           0, 9.113e-16, 103.919, 17834.191, Double.MaxValue }
Dim result As Integer

For Each value As Double In values
   Try
      result = Convert.ToInt32(value)
      Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _
                        value.GetType().Name, value, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("{0} is outside the range of the Int32 type.", value)
   End Try   
Next                                 
'    -1.79769313486232E+308 is outside the range of the Int32 type.
'    -13800000000 is outside the range of the Int32 type.
'    Converted the Double value '-1023.299' to the Int32 value -1023.
'    Converted the Double value '-12.98' to the Int32 value -13.
'    Converted the Double value '0' to the Int32 value 0.
'    Converted the Double value '9.113E-16' to the Int32 value 0.
'    Converted the Double value '103.919' to the Int32 value 104.
'    Converted the Double value '17834.191' to the Int32 value 17834.
'    1.79769313486232E+308 is outside the range of the Int32 type.

こちらもご覧ください

• Double
• Round

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(short value);

public static int ToInt32 (short value);

static member ToInt32 : int16 -> int

Public Shared Function ToInt32 (value As Short) As Integer

パラメーター

戻り値

value と等価の 32 ビット符号付き整数。

例

次の例では、16 ビット符号付き整数の配列内の各要素を整数に変換します。

short[] numbers= { Int16.MinValue, -1, 0, 121, 340, Int16.MaxValue };
int result;

foreach (short number in numbers)
{
   result = Convert.ToInt32(number);
   Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.",
                        number.GetType().Name, number,
                        result.GetType().Name, result);
}
// The example displays the following output:
//    Converted the Int16 value -32768 to a Int32 value -32768.
//    Converted the Int16 value -1 to a Int32 value -1.
//    Converted the Int16 value 0 to a Int32 value 0.
//    Converted the Int16 value 121 to a Int32 value 121.
//    Converted the Int16 value 340 to a Int32 value 340.
//    Converted the Int16 value 32767 to a Int32 value 32767.

let numbers = 
    [| Int16.MinValue; -1s; 0s; 121s; 340s; Int16.MaxValue |]

for number in numbers do
    let result = Convert.ToInt32 number
    printfn $"Converted the {number.GetType().Name} value {number} to a {result.GetType().Name} value {result}."
// The example displays the following output:
//    Converted the Int16 value -32768 to a Int32 value -32768.
//    Converted the Int16 value -1 to a Int32 value -1.
//    Converted the Int16 value 0 to a Int32 value 0.
//    Converted the Int16 value 121 to a Int32 value 121.
//    Converted the Int16 value 340 to a Int32 value 340.
//    Converted the Int16 value 32767 to a Int32 value 32767.

Dim numbers() As Short = { Int16.MinValue, -1, 0, 121, 340, Int16.MaxValue }
Dim result As Integer

For Each number As Short In numbers
   result = Convert.ToInt32(number)
   Console.WriteLine("Converted the {0} value {1} to a {2} value {3}.", _
                        number.GetType().Name, number, _
                        result.GetType().Name, result)
Next
' The example displays the following output:
'    Converted the Int16 value -32768 to a Int32 value -32768.
'    Converted the Int16 value -1 to a Int32 value -1.
'    Converted the Int16 value 0 to a Int32 value 0.
'    Converted the Int16 value 121 to a Int32 value 121.
'    Converted the Int16 value 340 to a Int32 value 340.
'    Converted the Int16 value 32767 to a Int32 value 32767.

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(int value);

public static int ToInt32 (int value);

static member ToInt32 : int -> int

Public Shared Function ToInt32 (value As Integer) As Integer

パラメーター

戻り値

value は変更されずに返されます。

ソース:

Convert.cs

ソース:

Convert.cs

ソース:

Convert.cs

public:
 static int ToInt32(System::Decimal value);

public static int ToInt32 (decimal value);

static member ToInt32 : decimal -> int

Public Shared Function ToInt32 (value As Decimal) As Integer

パラメーター

戻り値

最も近い 32 ビット符号付き整数に丸められた value。 value が 2 つの整数のちょうど中間にある場合は、偶数が返されます。つまり、4.5 は 4 に変換され、5.5 は 6 に変換されます。

例外

例

次の例では、値の配列 Decimal 内の各要素を整数に変換しようとしています。

decimal[] values= { Decimal.MinValue, -1034.23m, -12m, 0m, 147m,
                    199.55m, 9214.16m, Decimal.MaxValue };
int result;

foreach (decimal value in values)
{
   try {
      result = Convert.ToInt32(value);
      Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.",
                        value.GetType().Name, value,
                        result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("{0} is outside the range of the Int32 type.",
                        value);
   }
}
// The example displays the following output:
//    -79228162514264337593543950335 is outside the range of the Int32 type.
//    Converted the Decimal value '-1034.23' to the Int32 value -1034.
//    Converted the Decimal value '-12' to the Int32 value -12.
//    Converted the Decimal value '0' to the Int32 value 0.
//    Converted the Decimal value '147' to the Int32 value 147.
//    Converted the Decimal value '199.55' to the Int32 value 200.
//    Converted the Decimal value '9214.16' to the Int32 value 9214.
//    79228162514264337593543950335 is outside the range of the Int32 type.

let values = 
    [| Decimal.MinValue; -1034.23m; -12m; 0m; 147m
       199.55m; 9214.16m; Decimal.MaxValue |]

for value in values do
    try
        let result = Convert.ToInt32 value
        printfn $"Converted the {value.GetType().Name} value '{value}' to the {result.GetType().Name} value {result}."
    with :? OverflowException ->
        printfn $"{value} is outside the range of the Int32 type."
// The example displays the following output:
//    -79228162514264337593543950335 is outside the range of the Int32 type.
//    Converted the Decimal value '-1034.23' to the Int32 value -1034.
//    Converted the Decimal value '-12' to the Int32 value -12.
//    Converted the Decimal value '0' to the Int32 value 0.
//    Converted the Decimal value '147' to the Int32 value 147.
//    Converted the Decimal value '199.55' to the Int32 value 200.
//    Converted the Decimal value '9214.16' to the Int32 value 9214.
//    79228162514264337593543950335 is outside the range of the Int32 type.

Dim values() As Decimal = { Decimal.MinValue, -1034.23d, -12d, 0d, 147d, _
                            199.55d, 9214.16d, Decimal.MaxValue }
Dim result As Integer

For Each value As Decimal In values
   Try
      result = Convert.ToInt32(value)
      Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.", _
                        value.GetType().Name, value, _
                        result.GetType().Name, result)
   Catch e As OverflowException
      Console.WriteLine("{0} is outside the range of the Int32 type.", _
                        value)
   End Try   
Next                                  
' The example displays the following output:
'    -79228162514264337593543950335 is outside the range of the Int32 type.
'    Converted the Decimal value '-1034.23' to the Int32 value -1034.
'    Converted the Decimal value '-12' to the Int32 value -12.
'    Converted the Decimal value '0' to the Int32 value 0.
'    Converted the Decimal value '147' to the Int32 value 147.
'    Converted the Decimal value '199.55' to the Int32 value 200.
'    Converted the Decimal value '9214.16' to the Int32 value 9214.
'    79228162514264337593543950335 is outside the range of the Int32 type.

こちらもご覧ください

• Round