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PostMessage (user32)

C# Signature:

[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
static extern bool PostMessage(HandleRef hWnd, uint Msg, IntPtr wParam, IntPtr lParam);

VB.NET Signature:

<DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function PostMessage(ByVal hWnd As IntPtr, ByVal Msg As UInteger, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As Boolean
End Function

Oxygene.NET Signature:

[DllImport("user32.dll", SetLastError := true)]
class method PostMessage(hWnd: IntPtr; Msg: UInt32; wParam, lParam: IntPtr): Boolean; external;

User-Defined Types:



MSDN says: If the function fails, the return value is zero. To get extended error information, call GetLastError.

Tips & Tricks:

Please add some!

Sample Code:

A wrapper for PostMessage looking for errors:

    void PostMessageSafe( HandleRef hWnd, uint msg, IntPtr wParam, IntPtr lParam )
        bool returnValue = PostMessage( hWnd, msg, wParam, lParam );
        if( !returnValue )
        // An error occured
        throw new Win32Exception( Marshal.GetLastWin32Error() );

Alternative Managed API:

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PostMessage on MSDN

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