さまざまな型の配列のマーシャリング

更新 : 2007 年 11 月

このサンプルでは、次の種類の配列を渡す方法を示します。

  • 整数の配列を値渡しする方法。

  • 整数の配列を参照渡しする方法。サイズを変更できます。

  • 整数の多次元配列 (行列) を値渡しする方法。

  • 文字列の配列を値渡しする方法。

  • 整数を含む構造体の配列を渡す方法。

  • 文字列を含む構造体の配列を渡す方法。

配列を明示的に参照渡しでマーシャリングする場合を除き、既定の動作により配列は In パラメータとしてマーシャリングされます。InAttribute 属性および OutAttribute 属性を明示的に適用することで、この動作を変更できます。

Arrays のサンプルで使用するアンマネージ関数とその関数宣言を次に示します。

  • PinvokeLib.dll からエクスポートされる TestArrayOfInts

    int TestArrayOfInts(int* pArray, int pSize);
    
  • PinvokeLib.dll からエクスポートされる TestRefArrayOfInts

    int TestRefArrayOfInts(int** ppArray, int* pSize);
    
  • PinvokeLib.dll からエクスポートされる TestMatrixOfInts

    int TestMatrixOfInts(int pMatrix[][COL_DIM], int row);
    
  • PinvokeLib.dll からエクスポートされる TestArrayOfStrings

    int TestArrayOfStrings(char** ppStrArray, int size);
    
  • PinvokeLib.dll からエクスポートされる TestArrayOfStructs

    int TestArrayOfStructs(MYPOINT* pPointArray, int size);
    
  • PinvokeLib.dll からエクスポートされる TestArrayOfStructs2

    int TestArrayOfStructs2 (MYPERSON* pPersonArray, int size);
    

PinvokeLib.dll はカスタム アンマネージ ライブラリであり、上記の関数および 2 つの構造体変数 MYPOINTMYPERSON に関する実装を含んでいます。この構造体には次の要素が含まれます。

typedef struct _MYPOINT
{
   int x; 
   int y; 
} MYPOINT;

typedef struct _MYPERSON
{
   char* first; 
   char* last; 
} MYPERSON;

このサンプルでは、MyPoint 構造体と MyPerson 構造体に埋め込み型が含まれます。各メンバが出現する順番でメモリ内に順次配列されることを保証するために、StructLayoutAttribute 属性を設定します。

LibWrap クラスには、App クラスによって呼び出されるメソッドのセットが含まれます。配列の渡し方に関する詳細については、次のサンプルのコメントを参照してください。配列は参照型であり、既定により In パラメータとして渡されます。呼び出し元が結果を受け取るためには、配列を含む引数に対して明示的に InAttribute および OutAttribute を適用する必要があります。

次のコード例のソース コードは、.NET Framework「プラットフォーム呼び出しの技術サンプル」で提供されています。

プロトタイプの宣言

' Declares a managed structure for each unmanaged structure.
< StructLayout( LayoutKind.Sequential )> _
Public Structure MyPoint
   Public x As Integer
   Public y As Integer
   Public Sub New( x As Integer, y As Integer )
      Me.x = x
      Me.y = y
   End Sub 'New
End Structure 'MyPoint

< StructLayout( LayoutKind.Sequential, CharSet:=CharSet.Ansi )> _
Public Structure MyPerson
   Public first As String
   Public last As String
   Public Sub New( first As String, last As String )
      Me.first = first
      Me.last = last
   End Sub 'New
End Structure 'MyPerson

Public Class LibWrap
   ' Declares a managed prototype for an array of integers by value.
   ' The array size cannot be changed, but the array is copied back.
   Declare Function TestArrayOfInts Lib "..\LIB\PinvokeLib.dll" ( _
      <[In], Out> ByVal myArray() As Integer, ByVal size As Integer ) _
      As Integer

   ' Declares managed prototype for an array of integers by reference.
   ' The array size can change, but the array is not copied back 
   ' automatically because the marshaler does not know the resulting size.
   ' The copy must be performed manually.
   Declare Function TestRefArrayOfInts Lib "..\LIB\PinvokeLib.dll" ( _
      ByRef myArray As IntPtr, ByRef size As Integer ) As Integer

   ' Declares a managed prototype for a matrix of integers by value.
   Declare Function TestMatrixOfInts Lib "..\LIB\PinvokeLib.dll" ( _
      <[In], Out> ByVal matrix(,) As Integer, ByVal row As Integer ) _
      As Integer

   ' Declares a managed prototype for an array of strings by value.
   Declare Function TestArrayOfStrings Lib "..\LIB\PinvokeLib.dll" ( _
      <[In], Out> ByVal strArray() As String, ByVal size As Integer ) _
   As Integer
   
   ' Declares a managed prototype for an array of structures with 
   ' integers.
   Declare Function TestArrayOfStructs Lib "..\LIB\PinvokeLib.dll" ( _
      <[In], Out> ByVal pointArray() As MyPoint, _
      ByVal size As Integer ) As Integer
   
   ' Declares a managed prototype for an array of structures with strings.
   Declare Function TestArrayOfStructs2 Lib "..\LIB\PinvokeLib.dll" ( _
      <[In], Out> ByVal personArray() As MyPerson, ByVal size _
      As Integer ) As Integer
End Class 'LibWrap
// Declares a managed structure for each unmanaged structure.
[ StructLayout( LayoutKind.Sequential )]
public struct MyPoint 
{
   public int x; 
   public int y;
   public MyPoint( int x, int y )
   {
      this.x = x;
      this.y = y;
   }
}
[ StructLayout( LayoutKind.Sequential, CharSet=CharSet.Ansi )]
public struct MyPerson 
{
   public String first; 
   public String last;
   public MyPerson( String first, String last )
   {
      this.first = first;
      this.last = last;
   }
}

public class LibWrap
{
   // Declares a managed prototype for an array of integers by value.
   // The array size cannot be changed, but the array is copied back.
   [ DllImport( "..\\LIB\\PinvokeLib.dll" )]
   public static extern int TestArrayOfInts([In, Out] int[] array, int size );
   
   // Declares a managed prototype for an array of integers by reference.
   // The array size can change, but the array is not copied back 
   // automatically because the marshaler does not know the resulting size.
   // The copy must be performed manually.
   [ DllImport( "..\\LIB\\PinvokeLib.dll" )]
   public static extern int TestRefArrayOfInts( ref IntPtr array, 
      ref int size );
   
   // Declares a managed prototype for a matrix of integers by value.
   [ DllImport( "..\\LIB\\PinvokeLib.dll" )]
   public static extern int TestMatrixOfInts([In, Out] int[,] pMatrix, 
      int row );   
   // Declares a managed prototype for an array of strings by value.
   [ DllImport( "..\\LIB\\PinvokeLib.dll" )]
   public static extern int TestArrayOfStrings( [In, Out] 
      String[] stringArray, int size );
   
   // Declares a managed prototype for an array of structures with integers.
   [ DllImport( "..\\LIB\\PinvokeLib.dll" )]
   public static extern int TestArrayOfStructs([In, Out] MyPoint[] 
      pointArray, int size ); 
   
   // Declares a managed prototype for an array of structures with strings.
   [ DllImport( "..\\LIB\\PinvokeLib.dll" )]
   public static extern int TestArrayOfStructs2( [In, Out] 
      MyPerson[] personArray, int size );
}

関数の呼び出し

Public Class App
   Public Shared Sub Main()
      ' array ByVal
      Dim array1(9) As Integer
      
      Console.WriteLine( "Integer array passed ByVal before call:" )
      Dim i As Integer
      For i = 0 To array1.Length - 1
         array1(i) = i
         Console.Write( " " & array1(i) )
      Next i
      
      Dim sum1 As Integer = LibWrap.TestArrayOfInts( array1, array1._
         Length )
      Console.WriteLine( ControlChars.CrLf & "Sum of elements:" & sum1 )
      Console.WriteLine( ControlChars.CrLf & "Integer array passed _
         ByVal after call:" )
      For Each i In  array1
         Console.Write( " " & i )
      Next i
      
      ' array ByRef
      Dim array2(9) As Integer
      Dim arraySize As Integer = array2.Length
      Console.WriteLine( ControlChars.CrLf & ControlChars.CrLf & _
         "Integer array passed ByRef before call:" )
      For i = 0 To array2.Length - 1
         array2(i) = i
         Console.Write( " " & array2(i) )
      Next i
      Dim buffer As IntPtr = Marshal.AllocCoTaskMem( Marshal.SizeOf( _
         arraySize ) * array2.Length )
      Marshal.Copy( array2, 0, buffer, array2.Length )
      Dim sum2 As Integer = LibWrap.TestRefArrayOfInts( buffer, _
         arraySize )
      Console.WriteLine( ControlChars.CrLf & "Sum of elements:" & sum2 )
      
      If arraySize > 0 Then
         Dim arrayRes( arraySize - 1 ) As Integer
         Marshal.Copy( buffer, arrayRes, 0, arraySize )
         Marshal.FreeCoTaskMem( buffer )
         
         Console.WriteLine( ControlChars.CrLf & "Integer array _
           passed ByRef after call:" )
         For Each i In  arrayRes
            Console.Write( " " & i )
         Next i
      Else
         Console.WriteLine( ControlChars.CrLf & "Array after call _
           is empty" )
      End If
      
      ' matrix ByVal 
      Const [DIM] As Integer = 4
      Dim matrix([DIM], [DIM]) As Integer
      
      Console.WriteLine( ControlChars.CrLf & ControlChars.CrLf & _
         "Matrix before call:" )
      For i = 0 To [DIM]
         Dim j As Integer
         For j = 0 To [DIM]
            matrix(i, j) = j
            Console.Write( " " & matrix(i, j) )
         Next j
         Console.WriteLine( "" )
      Next i

      Dim sum3 As Integer = LibWrap.TestMatrixOfInts( matrix, [DIM] + 1 )
      Console.WriteLine( ControlChars.CrLf & "Sum of elements:" & sum3 )
      Console.WriteLine( ControlChars.CrLf & "Matrix after call:" )
      For i = 0 To [DIM]
         Dim j As Integer
         For j = 0 To [DIM]
            Console.Write( " " & matrix(i, j) )
         Next j
         Console.WriteLine( "" )
      Next i

      ' string array ByVal 
      Dim strArray As String() =  { "one", "two", "three", "four", _
        "five" }
      Console.WriteLine( ControlChars.CrLf & ControlChars.CrLf & _
        "String array before call:" )
      Dim s As String
      For Each s In  strArray
         Console.Write( " " & s )
      Next s 
      Dim lenSum As Integer = LibWrap.TestArrayOfStrings( _
         strArray, strArray.Length )
      Console.WriteLine( ControlChars.CrLf & _
         "Sum of string lengths:" & lenSum )
      Console.WriteLine( ControlChars.CrLf & "String array after call:" )
      For Each s In  strArray
         Console.Write( " " & s )
      Next s

      ' struct array ByVal 
      Dim points As MyPoint() = { New MyPoint(1, 1), New MyPoint(2, 2), _
         New MyPoint(3, 3) }
      Console.WriteLine( ControlChars.CrLf & ControlChars.CrLf & _
         "Points array before call:" )
      Dim p As MyPoint
      For Each p In  points
         Console.WriteLine( "x = {0}, y = {1}", p.x, p.y )
      Next p 
      Dim allSum As Integer = LibWrap.TestArrayOfStructs( points, _
         points.Length )
      Console.WriteLine( ControlChars.CrLf & "Sum of points:" & allSum )
      Console.WriteLine( ControlChars.CrLf & "Points array after call:" )
      For Each p In  points
         Console.WriteLine( "x = {0}, y = {1}", p.x, p.y )
      Next p 
      
      ' struct with strings array ByVal 
      Dim persons As MyPerson() =  { _New MyPerson( "Kim", "Akers" ), _
         New MyPerson( "Adam", "Barr" ), _
         New MyPerson( "Jo", "Brown" )}
      Console.WriteLine( ControlChars.CrLf & ControlChars.CrLf & _
         "Persons array before call:" )
      Dim pe As MyPerson
      For Each pe In  persons
         Console.WriteLine( "first = {0}, last = {1}", pe.first, pe.last )
      Next pe 
      
      Dim namesSum As Integer = LibWrap.TestArrayOfStructs2( persons, _
         persons.Length )
      Console.WriteLine( ControlChars.CrLf & "Sum of name lengths:" & _
         namesSum )
      Console.WriteLine( ControlChars.CrLf & ControlChars._
         CrLf & "Persons array after call:" )
      For Each pe In  persons
         Console.WriteLine( "first = {0}, last = {1}", pe.first, pe.last )
      Next pe
   End Sub 'Main
End Class 'App
public class App
{
   public static void Main()
   {
      // array ByVal 
      int[] array1 = new int[ 10 ];
      Console.WriteLine( "Integer array passed ByVal before call:" );
      for( int i = 0; i < array1.Length; i++ )
      {
         array1[ i ] = i;
         Console.Write( " " + array1[ i ] );
      }
      int sum1 = LibWrap.TestArrayOfInts( array1, array1.Length );
      Console.WriteLine( "\nSum of elements:" + sum1 );
      Console.WriteLine( "\nInteger array passed ByVal after call:" );
      
      foreach( int i in array1 )
      {
         Console.Write( " " + i );
      }   
      
      // array ByRef 
      int[] array2 = new int[ 10 ];
      int size = array2.Length;
      Console.WriteLine( "\n\nInteger array passed ByRef before call:" );
      for( int i = 0; i < array2.Length; i++ )
      {
         array2[ i ] = i;
         Console.Write( " " + array2[ i ] );
      }
      IntPtr buffer = Marshal.AllocCoTaskMem( Marshal.SizeOf( size ) 
         * array2.Length );
      Marshal.Copy( array2, 0, buffer, array2.Length );
      
      int sum2 = LibWrap.TestRefArrayOfInts( ref buffer, ref size );
      Console.WriteLine( "\nSum of elements:" + sum2 );
      if( size > 0 )
      {
         int[] arrayRes = new int[ size ];
         Marshal.Copy( buffer, arrayRes, 0, size );
         Marshal.FreeCoTaskMem( buffer );
         Console.WriteLine( "\nInteger array passed ByRef after call:" );
         foreach( int i in arrayRes )
         {
            Console.Write( " " + i );
         }
      }
      else
         Console.WriteLine( "\nArray after call is empty" );
         
      // matrix ByVal 
      const int DIM = 5;
      int[,] matrix = new int[ DIM, DIM ];
      
      Console.WriteLine( "\n\nMatrix before call:" );
      for( int i = 0; i < DIM; i++ )
      {
         for( int j = 0; j < DIM; j++ )
         {
            matrix[ i, j ] = j;
            Console.Write( " " + matrix[ i, j ] );
         }
         Console.WriteLine( "" );
      }
      int sum3 = LibWrap.TestMatrixOfInts( matrix, DIM );
      Console.WriteLine( "\nSum of elements:" + sum3 );
      Console.WriteLine( "\nMatrix after call:" );
      for( int i = 0; i < DIM; i++ )
      {
         for( int j = 0; j < DIM; j++ )
         {
            Console.Write( " " + matrix[ i, j ] );
         }
         Console.WriteLine( "" );
      }
      
      // string array ByVal 
      String[] strArray = { "one", "two", "three", "four", "five" };
      Console.WriteLine( "\n\nString array before call:" );
      foreach( String s in strArray )
         Console.Write( " "+ s );
      int lenSum = LibWrap.TestArrayOfStrings( strArray, strArray.Length );
      Console.WriteLine( "\nSum of string lengths:" + lenSum );
      Console.WriteLine( "\nString array after call:" );
      foreach( String s in strArray )
      {
         Console.Write( " " + s );
      }   
      
      // struct array ByVal 
      MyPoint[] points = { new MyPoint(1,1), new MyPoint(2,2), new MyPoint(3,3) };
      Console.WriteLine( "\n\nPoints array before call:" );
      foreach( MyPoint p in points )
         Console.WriteLine( "x = {0}, y = {1}", p.x, p.y );
      int allSum = LibWrap.TestArrayOfStructs( points, points.Length );
      Console.WriteLine( "\nSum of points:" + allSum );
      Console.WriteLine( "\nPoints array after call:" );
      foreach( MyPoint p in points )
         Console.WriteLine( "x = {0}, y = {1}", p.x, p.y );      
         
      // struct with strings array ByVal 
      MyPerson[] persons = { new MyPerson( "Kim", "Akers" ), 
      new MyPerson( "Adam", "Barr" ), new MyPerson( "Jo", "Brown" )};
      
      Console.WriteLine( "\n\nPersons array before call:" );
      foreach( MyPerson pe in persons )
        Console.WriteLine( "first = {0}, last = {1}", pe.first, pe.last );
      int namesSum = LibWrap.TestArrayOfStructs2( persons, persons.Length );
      Console.WriteLine( "\nSum of name lengths:" + namesSum );
      Console.WriteLine( "\n\nPersons array after call:" );
      foreach( MyPerson pe in persons )
        Console.WriteLine( "first = {0}, last = {1}", pe.first, pe.last );
   }
}

参照

概念

型の配列のマーシャリング

プラットフォーム呼び出しのデータ型

マネージ コードでのプロトタイプの作成