Convert.ToInt32 メソッド

指定した値を 32 ビット符号付き整数に変換します。

オーバーロードの一覧

指定した Boolean 値を等価の 32 ビット符号付き整数に変換します。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(Boolean) As Integer

[C#] public static int ToInt32(bool);

[C++] public: static int ToInt32(bool);

[JScript] public static function ToInt32(Boolean) : int;

指定した 8 ビット符号なし整数の値を等価の 32 ビット符号付き整数に変換します。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(Byte) As Integer

[C#] public static int ToInt32(byte);

[C++] public: static int ToInt32(unsigned char);

[JScript] public static function ToInt32(Byte) : int;

指定した Unicode 文字の値を等価の 32 ビット符号付き整数に変換します。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(Char) As Integer

[C#] public static int ToInt32(char);

[C++] public: static int ToInt32(__wchar_t);

[JScript] public static function ToInt32(Char) : int;

このメソッドを呼び出すと、必ず InvalidCastException がスローされます。

[Visual Basic] Overloads Public Shared Function ToInt32(DateTime) As Integer

[C#] public static int ToInt32(DateTime);

[C++] public: static int ToInt32(DateTime);

[JScript] public static function ToInt32(DateTime) : int;

指定した Decimal 数の値を等価の 32 ビット符号付き整数に変換します。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(Decimal) As Integer

[C#] public static int ToInt32(decimal);

[C++] public: static int ToInt32(Decimal);

[JScript] public static function ToInt32(Decimal) : int;

指定した倍精度浮動小数点数の値を等価の 32 ビット符号付き整数に変換します。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(Double) As Integer

[C#] public static int ToInt32(double);

[C++] public: static int ToInt32(double);

[JScript] public static function ToInt32(double) : int;

指定した 16 ビット符号付き整数の値を等価の 32 ビット符号付き整数に変換します。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(Short) As Integer

[C#] public static int ToInt32(short);

[C++] public: static int ToInt32(short);

[JScript] public static function ToInt32(Int16) : int;

指定した 32 ビット符号付き整数が返されます。実際の変換は行われません。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(Integer) As Integer

[C#] public static int ToInt32(int);

[C++] public: static int ToInt32(int);

[JScript] public static function ToInt32(int) : int;

指定した 64 ビット符号付き整数の値を等価の 32 ビット符号付き整数に変換します。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(Long) As Integer

[C#] public static int ToInt32(long);

[C++] public: static int ToInt32(__int64);

[JScript] public static function ToInt32(long) : int;

指定した Object の値を 32 ビット符号付き整数に変換します。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(Object) As Integer

[C#] public static int ToInt32(object);

[C++] public: static int ToInt32(Object*);

[JScript] public static function ToInt32(Object) : int;

指定した 8 ビット符号付き整数の値を等価の 32 ビット符号付き整数に変換します。このメソッドは、CLS と互換性がありません。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(SByte) As Integer

[C#] public static int ToInt32(sbyte);

[C++] public: static int ToInt32(char);

[JScript] public static function ToInt32(SByte) : int;

指定した単精度浮動小数点数の値を等価の 32 ビット符号付き整数に変換します。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(Single) As Integer

[C#] public static int ToInt32(float);

[C++] public: static int ToInt32(float);

[JScript] public static function ToInt32(float) : int;

指定した String 形式の数値を、それと等価な 32 ビット符号付き整数に変換します。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(String) As Integer

[C#] public static int ToInt32(string);

[C++] public: static int ToInt32(String*);

[JScript] public static function ToInt32(String) : int;

指定した 32 ビット符号なし整数の値を等価の 16 ビット符号付き整数に変換します。このメソッドは、CLS と互換性がありません。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(UInt16) As Integer

[C#] public static int ToInt32(ushort);

[C++] public: static int ToInt32(unsigned short);

[JScript] public static function ToInt32(UInt16) : int;

指定した 32 ビット符号なし整数の値を等価の 32 ビット符号付き整数に変換します。このメソッドは、CLS と互換性がありません。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(UInt32) As Integer

[C#] public static int ToInt32(uint);

[C++] public: static int ToInt32(unsigned int);

[JScript] public static function ToInt32(UInt32) : int;

指定した 64 ビット符号なし整数の値を等価の 32 ビット符号付き整数に変換します。このメソッドは、CLS と互換性がありません。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(UInt64) As Integer

[C#] public static int ToInt32(ulong);

[C++] public: static int ToInt32(unsigned __int64);

[JScript] public static function ToInt32(UInt64) : int;

カルチャに固有の指定した書式情報を使用して、指定した Object の値を 32 ビット符号付き整数に変換します。

[Visual Basic] Overloads Public Shared Function ToInt32(Object, IFormatProvider) As Integer

[C#] public static int ToInt32(object, IFormatProvider);

[C++] public: static int ToInt32(Object*, IFormatProvider*);

[JScript] public static function ToInt32(Object, IFormatProvider) : int;

カルチャに固有の指定した書式情報を使用して、数値の特定の String 形式を等価の 32 ビット符号付き整数に変換します。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(String, IFormatProvider) As Integer

[C#] public static int ToInt32(string, IFormatProvider);

[C++] public: static int ToInt32(String*, IFormatProvider*);

[JScript] public static function ToInt32(String, IFormatProvider) : int;

指定した基数での数値の String 形式を等価の 32 ビット符号付き整数に変換します。

.NET Compact Framework でもサポート。

[Visual Basic] Overloads Public Shared Function ToInt32(String, Integer) As Integer

[C#] public static int ToInt32(string, int);

[C++] public: static int ToInt32(String*, int);

[JScript] public static function ToInt32(String, int) : int;

使用例

[Visual Basic, C#, C++] IFormatProvider オブジェクトを使用し、 String 形式の Int32 (32 ビット整数) を ToInt32 メソッドで変換するコード例を次に示します。

[Visual Basic, C#, C++] メモ   ここでは、ToInt32 のオーバーロード形式のうちの 1 つだけについて、使用例を示します。その他の例については、各オーバーロード形式のトピックを参照してください。

 
' Example of the Convert.ToInt32( String ) and 
' Convert.ToInt32( String, IFormatProvider ) methods.
Imports System
Imports System.Globalization
Imports Microsoft.VisualBasic

Module ToInt32ProviderDemo

    Dim format As String = "{0,-20}{1,-20}{2}"

    ' Get the exception type name; remove the namespace prefix.
    Function GetExceptionType( ex As Exception ) As String

        Dim exceptionType   As String = ex.GetType( ).ToString( )
        Return exceptionType.Substring( _
            exceptionType.LastIndexOf( "."c ) + 1 )
    End Function

    Sub ConvertToInt32( numericStr As String, _
        provider As IFormatProvider )

        Dim defaultValue    As Object
        Dim providerValue   As Object

        ' Convert numericStr to Int32 without a format provider.
        Try
            defaultValue = Convert.ToInt32( numericStr )
        Catch ex As Exception
            defaultValue = GetExceptionType( ex )
        End Try

        ' Convert numericStr to Int32 with a format provider.
        Try
            providerValue = Convert.ToInt32( numericStr, provider )
        Catch ex As Exception
            providerValue = GetExceptionType( ex )
        End Try

        Console.WriteLine( format, numericStr, _
            defaultValue, providerValue )
    End Sub

    Sub Main( )

        ' Create a NumberFormatInfo object and set several of its
        ' properties that apply to numbers.
        Dim provider  As NumberFormatInfo = new NumberFormatInfo( )

        ' These properties affect the conversion.
        provider.NegativeSign = "neg "
        provider.PositiveSign = "pos "

        ' These properties do not affect the conversion.
        ' The input string cannot have decimal and group separators.
        provider.NumberDecimalSeparator = "."
        provider.NumberGroupSeparator = ","
        provider.NumberGroupSizes = New Integer( ) { 3 }
        provider.NumberNegativePattern = 0

        Console.WriteLine( "This example of" & vbCrLf & _
            "  Convert.ToInt32( String ) and " & vbCrLf & _
            "  Convert.ToInt32( String, IFormatProvider ) " & _
            vbCrLf & "generates the following output. It " & _
            "converts several strings to " & vbCrLf & "Integer " & _
            "values, using default formatting " & _
            "or a NumberFormatInfo object." & vbCrLf )
        Console.WriteLine( format, "String to convert", _
            "Default/exception", "Provider/exception" )
        Console.WriteLine( format, "-----------------", _
            "-----------------", "------------------" )

        ' Convert strings, with and without an IFormatProvider.
        ConvertToInt32( "123456789", provider )
        ConvertToInt32( "+123456789", provider )
        ConvertToInt32( "pos 123456789", provider )
        ConvertToInt32( "-123456789", provider )
        ConvertToInt32( "neg 123456789", provider )
        ConvertToInt32( "123456789.", provider )
        ConvertToInt32( "123,456,789", provider )
        ConvertToInt32( "(123456789)", provider )
        ConvertToInt32( "2147483648", provider )
        ConvertToInt32( "-2147483649", provider )
    End Sub 
End Module 

' This example of
'   Convert.ToInt32( String ) and
'   Convert.ToInt32( String, IFormatProvider )
' generates the following output. It converts several strings to
' Integer values, using default formatting or a NumberFormatInfo object.
' 
' String to convert   Default/exception   Provider/exception
' -----------------   -----------------   ------------------
' 123456789           123456789           123456789
' +123456789          123456789           FormatException
' pos 123456789       FormatException     123456789
' -123456789          -123456789          FormatException
' neg 123456789       FormatException     -123456789
' 123456789.          FormatException     FormatException
' 123,456,789         FormatException     FormatException
' (123456789)         FormatException     FormatException
' 2147483648          OverflowException   OverflowException
' -2147483649         OverflowException   FormatException

[C#] 
// Example of the Convert.ToInt32( string ) and 
// Convert.ToInt32( string, IFormatProvider ) methods.
using System;
using System.Globalization;

class ToInt32ProviderDemo
{
    static string format = "{0,-20}{1,-20}{2}";

     // Get the exception type name; remove the namespace prefix.
    static string GetExceptionType( Exception ex )
    {
        string exceptionType = ex.GetType( ).ToString( );
        return exceptionType.Substring( 
            exceptionType.LastIndexOf( '.' ) + 1 );
    }

    static void ConvertToInt32( string numericStr, 
        IFormatProvider provider )
    {
        object defaultValue;
        object providerValue;

        // Convert numericStr to Int32 without a format provider.
        try
        {
            defaultValue = Convert.ToInt32( numericStr );
        }
        catch( Exception ex )
        {
            defaultValue = GetExceptionType( ex );
        }

        // Convert numericStr to Int32 with a format provider.
        try
        {
            providerValue = Convert.ToInt32( numericStr, provider );
        }
        catch( Exception ex )
        {
            providerValue = GetExceptionType( ex );
        }

        Console.WriteLine( format, numericStr, 
            defaultValue, providerValue );
    }

    public static void Main( )
    {
        // Create a NumberFormatInfo object and set several of its
        // properties that apply to numbers.
        NumberFormatInfo provider = new NumberFormatInfo();

        // These properties affect the conversion.
        provider.NegativeSign = "neg ";
        provider.PositiveSign = "pos ";

        // These properties do not affect the conversion.
        // The input string cannot have decimal and group separators.
        provider.NumberDecimalSeparator = ".";
        provider.NumberGroupSeparator = ",";
        provider.NumberGroupSizes = new int[ ] { 3 };
        provider.NumberNegativePattern = 0;

        Console.WriteLine("This example of\n" +
            "  Convert.ToInt32( string ) and \n" +
            "  Convert.ToInt32( string, IFormatProvider ) " +
            "\ngenerates the following output. It converts " +
            "several strings to \nint values, using " +
            "default formatting or a NumberFormatInfo object.\n" );
        Console.WriteLine( format, "String to convert", 
            "Default/exception", "Provider/exception" );
        Console.WriteLine( format, "-----------------", 
            "-----------------", "------------------" );

        // Convert strings, with and without an IFormatProvider.
        ConvertToInt32( "123456789", provider );
        ConvertToInt32( "+123456789", provider );
        ConvertToInt32( "pos 123456789", provider );
        ConvertToInt32( "-123456789", provider );
        ConvertToInt32( "neg 123456789", provider );
        ConvertToInt32( "123456789.", provider );
        ConvertToInt32( "123,456,789", provider );
        ConvertToInt32( "(123456789)", provider );
        ConvertToInt32( "2147483648", provider );
        ConvertToInt32( "-2147483649", provider );
    }
}

/*
This example of
  Convert.ToInt32( string ) and
  Convert.ToInt32( string, IFormatProvider )
generates the following output. It converts several strings to
int values, using default formatting or a NumberFormatInfo object.

String to convert   Default/exception   Provider/exception
-----------------   -----------------   ------------------
123456789           123456789           123456789
+123456789          123456789           FormatException
pos 123456789       FormatException     123456789
-123456789          -123456789          FormatException
neg 123456789       FormatException     -123456789
123456789.          FormatException     FormatException
123,456,789         FormatException     FormatException
(123456789)         FormatException     FormatException
2147483648          OverflowException   OverflowException
-2147483649         OverflowException   FormatException
*/ 

[C++] 
// Example of the Convert::ToInt32( String* ) and 
// Convert::ToInt32( String*, IFormatProvider* ) methods.
#using <mscorlib.dll>
using namespace System;
using namespace System::Globalization;

const __wchar_t* protoFmt = L"{0,-20}{1,-20}{2}" ;

// Get the exception type name; remove the namespace prefix.
String* GetExceptionType( Exception* ex )
{
    String* exceptionType = ex->GetType( )->ToString( );
    return exceptionType->Substring( 
        exceptionType->LastIndexOf( '.' ) + 1 );
}

void ConvertToInt32( String* numericStr, IFormatProvider* provider )
{
    Object* defaultValue;
    Object* providerValue;

    // Convert numericStr to Int32 without a format provider.
    try
    {
        defaultValue = __box( Convert::ToInt32( numericStr ) );
    }
    catch( Exception* ex )
    {
        defaultValue = GetExceptionType( ex );
    }

    // Convert numericStr to Int32 with a format provider.
    try
    {
        providerValue = __box( Convert::ToInt32( 
            numericStr, provider ) );
    }
    catch( Exception* ex )
    {
        providerValue = GetExceptionType( ex );
    }

    Console::WriteLine( new String( protoFmt ), numericStr, 
        defaultValue, providerValue );
}

void main( )
{
    // Create a NumberFormatInfo object and set several of its
    // properties that apply to numbers.
    NumberFormatInfo* provider = new NumberFormatInfo( );

    // These properties affect the conversion.
    provider->NegativeSign = S"neg ";
    provider->PositiveSign = S"pos ";

    // These properties do not affect the conversion.
    // The input string cannot have decimal and group separators.
    provider->NumberDecimalSeparator = S".";
    provider->NumberGroupSeparator = S",";
    Int32 sizes __gc [ ] = { 3 };
    provider->NumberGroupSizes = sizes;
    provider->NumberNegativePattern = 0;

    Console::WriteLine(S"This example of\n" 
        S"  Convert::ToInt32( String* ) and \n" 
        S"  Convert::ToInt32( String*, IFormatProvider* ) " 
        S"\ngenerates the following output. It converts " 
        S"several strings to \nint values, using " 
        S"default formatting or a NumberFormatInfo object.\n" );
    Console::WriteLine( new String( protoFmt ), S"String to convert", 
        S"Default/exception", S"Provider/exception" );
    Console::WriteLine( new String( protoFmt ), S"-----------------", 
        S"-----------------", S"------------------" );

    // Convert strings, with and without an IFormatProvider.
    ConvertToInt32( S"123456789", provider );
    ConvertToInt32( S"+123456789", provider );
    ConvertToInt32( S"pos 123456789", provider );
    ConvertToInt32( S"-123456789", provider );
    ConvertToInt32( S"neg 123456789", provider );
    ConvertToInt32( S"123456789.", provider );
    ConvertToInt32( S"123,456,789", provider );
    ConvertToInt32( S"(123456789)", provider );
    ConvertToInt32( S"2147483648", provider );
    ConvertToInt32( S"-2147483649", provider );
}

/*
This example of
  Convert::ToInt32( String* ) and
  Convert::ToInt32( String*, IFormatProvider* )
generates the following output. It converts several strings to
int values, using default formatting or a NumberFormatInfo object.

String to convert   Default/exception   Provider/exception
-----------------   -----------------   ------------------
123456789           123456789           123456789
+123456789          123456789           FormatException
pos 123456789       FormatException     123456789
-123456789          -123456789          FormatException
neg 123456789       FormatException     -123456789
123456789.          FormatException     FormatException
123,456,789         FormatException     FormatException
(123456789)         FormatException     FormatException
2147483648          OverflowException   OverflowException
-2147483649         OverflowException   FormatException
*/ 

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参照

Convert クラス | Convert メンバ | System 名前空間