LayoutKind Enum

Definition

public enum class LayoutKind

public enum LayoutKind

[System.Serializable]
public enum LayoutKind

[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public enum LayoutKind

type LayoutKind = 

[<System.Serializable>]
type LayoutKind = 

[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type LayoutKind = 

Public Enum LayoutKind

Inheritance

Object

ValueType

Enum

LayoutKind

Attributes

SerializableAttribute ComVisibleAttribute

Fields

Examples

The following example shows the managed declaration of the PtInRect function, which checks whether a point lies within a rectangle, and defines a Point structure with Sequential layout and a Rect structure with Explicit layout.

enum class Bool
{
 False = 0,
 True
};


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

ref class NativeMethods
{
public:

 [DllImport("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 = NativeMethods::PtInRect( &myRect, myPoint );
 if ( bPointInRect == Bool::True )
 Console::WriteLine( "Point lies within the Rect" );
 else
 Console::WriteLine( "Point did not lie within the Rect" );
 }
 catch ( Exception^ e ) 
 {
 Console::WriteLine( "Exception : {0}", e->Message );
 }

}

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;
}

internal static class NativeMethods
{
 [DllImport("user32.dll", CallingConvention=CallingConvention.StdCall)]
 internal 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 = NativeMethods.PtInRect(ref myRect, myPoint);
 if(bPointInRect == Bool.True)
 Console.WriteLine("Point lies within the Rect");
 else
 Console.WriteLine("Point did not lie within the Rect");
 }
 catch(Exception e)
 {
 Console.WriteLine("Exception : " + e.Message);
 }
 }
}

' The program shows a managed declaration of the PtInRect function and defines Point
' structure with sequential layout and Rect structure with explicit layout. The PtInRect
' checks the point lies within the rectangle or not.
Imports System.Runtime.InteropServices

 Enum Bool
 [False] = 0
 [True]
 End Enum 
 <StructLayout(LayoutKind.Sequential)> _
 Public Structure Point
 Public x As Integer
 Public y As Integer
 End Structure 
 
 <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 
 
 
 Friend Class NativeMethods
 
 <DllImport("user32.dll", CallingConvention := CallingConvention.StdCall)> _
 Friend Shared Function PtInRect(ByRef r As Rect, p As Point) As Bool
 End Function	
 End Class
 
 
 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 = NativeMethods.PtInRect(myRect, myPoint)
 If bPointInRect = Bool.True Then
 Console.WriteLine("Point lies within the Rect")
 Else
 Console.WriteLine("Point did not lie within the Rect")
 End If
 Catch e As Exception
 Console.WriteLine(("Exception : " + e.Message.ToString()))
 End Try
 End Sub 
 End Class

Remarks

This enumeration is used with StructLayoutAttribute. The common language runtime uses the Auto layout value by default. To reduce layout-related problems associated with the Auto value, C#, Visual Basic, and C++ compilers specify Sequential layout for value types.