LayoutKind 列挙体

アンマネージ コードにエクスポートするときにオブジェクトのレイアウトを制御します。

<Serializable>
Public Enum LayoutKind
[C#]
[Serializable]
public enum LayoutKind
[C++]
[Serializable]
__value public enum LayoutKind
[JScript]
public
   Serializable
enum LayoutKind

解説

この列挙体は、 StructLayoutAttribute で使用されます。共通言語ランタイムは既定で、 Auto レイアウトを使用します。 Auto 値にかかわるレイアウト関連の問題の発生を防ぐため、C#、Visual Basic .NET、および C++ のコンパイラは、値型に対して Sequential レイアウトを指定します。

メンバ

使用例

[Visual Basic, C#, C++] PtInRect 関数のマネージ宣言の例を次に示します。この関数は、特定の点が四角形内に存在するかどうかを確認し、 Point 構造体を Sequential レイアウトで定義し、 Rect 構造体を Explicit レイアウトを定義します。

 
Enum Bool
   [False] = 0
   [True]
End Enum 'Bool
<StructLayout(LayoutKind.Sequential)>  _
Public Structure Point
   Public x As Integer
   Public y As Integer
End Structure 'Point

<StructLayout(LayoutKind.Explicit)>  _   
Public Structure Rect
   <FieldOffset(0)> Public left As Integer
   <FieldOffset(4)> Public top As Integer
   <FieldOffset(8)> Public right As Integer
   <FieldOffset(12)> Public bottom As Integer
End Structure 'Rect


Class LibWrapper
   
   <DllImport("user32.dll", CallingConvention := CallingConvention.StdCall)>  _
   Public Shared Function PtInRect(ByRef r As Rect, p As Point) As Bool
   End Function    
End Class 'LibWrapper


Class TestApplication
   
   Public Shared Sub Main()
      Try
         Dim bPointInRect As Bool = 0
         Dim myRect As New Rect()
         myRect.left = 10
         myRect.right = 100
         myRect.top = 10
         myRect.bottom = 100
         Dim myPoint As New Point()
         myPoint.x = 50
         myPoint.y = 50
         bPointInRect = LibWrapper.PtInRect(myRect, myPoint)
         If bPointInRect = Bool.True Then
            Console.WriteLine("Point lies within the Rect")
         Else
            Console.WriteLine("Point did not lies within the Rect")
         End If
      Catch e As Exception
         Console.WriteLine(("Exception : " + e.Message.ToString()))
      End Try
   End Sub 'Main
End Class 'TestApplication

[C#] 
enum Bool
{
   False = 0,
   True
};
[StructLayout(LayoutKind.Sequential)]
public struct Point 
{
   public int x;
   public int y;
}   

[StructLayout(LayoutKind.Explicit)]
public struct Rect 
{
   [FieldOffset(0)] public int left;
   [FieldOffset(4)] public int top;
   [FieldOffset(8)] public int right;
   [FieldOffset(12)] public int bottom;
}   

class LibWrapper
{
   [DllImport("user32.dll", CallingConvention=CallingConvention.StdCall)]
   public static extern Bool PtInRect(ref Rect r, Point p);
};

class TestApplication
{
   public static void Main()
   {
      try
      {
         Bool bPointInRect = 0;
         Rect myRect = new Rect();
         myRect.left = 10;
         myRect.right = 100;
         myRect.top = 10;
         myRect.bottom = 100;
         Point myPoint = new Point();
         myPoint.x = 50;
         myPoint.y = 50;
         bPointInRect = LibWrapper.PtInRect(ref myRect, myPoint);
         if(bPointInRect == Bool.True)
            Console.WriteLine("Point lies within the Rect");
         else
            Console.WriteLine("Point did not lies within the Rect");
      }
      catch(Exception e)
      {
         Console.WriteLine("Exception : " + e.Message);
      }
   }
}

[C++] 
__value enum Bool {
    False = 0,
    True
};

[StructLayout(LayoutKind::Sequential)]
__value struct Point {
public:
    int  x;
public:
    int  y;
};

[StructLayout(LayoutKind::Explicit)]
__value struct Rect {
public:
    [FieldOffset(0)] 
    int  left;
    [FieldOffset(4)]
    int  top;
    [FieldOffset(8)] 
    int  right;
    [FieldOffset(12)] 
    int  bottom;
};

__gc class LibWrapper {
public:
[DllImport(S"user32.dll", CallingConvention=CallingConvention::StdCall)]
static Bool PtInRect(Rect* r, Point p);
};

    int main() {
        try {
            Bool bPointInRect = (Bool)0;
            Rect myRect = Rect();
            myRect.left = 10;
            myRect.right = 100;
            myRect.top = 10;
            myRect.bottom = 100;
            Point myPoint = Point();
            myPoint.x = 50;
            myPoint.y = 50;
            bPointInRect = LibWrapper::PtInRect(&myRect, myPoint);
            if (bPointInRect == Bool::True)
                Console::WriteLine(S"Point lies within the Rect");
            else
                Console::WriteLine(S"Point did not lie within the Rect");
        } catch (Exception* e) {
            Console::WriteLine(S"Exception : {0}", e->Message);
        }
    }

[JScript] JScript のサンプルはありません。Visual Basic、C#、および C++ のサンプルを表示するには、このページの左上隅にある言語のフィルタ ボタン をクリックします。

必要条件

名前空間: System.Runtime.InteropServices

プラットフォーム: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 ファミリ, .NET Compact Framework - Windows CE .NET

アセンブリ: Mscorlib (Mscorlib.dll 内)

参照

System.Runtime.InteropServices 名前空間