Obtains a copy of the window region of a window
_WinAPI_GetWindowRgn ( $hWnd, $hRgn )
|$hWnd||Handle to the window whose window region is to be obtained.|
|$hRgn||Handle to the region which will be modified to represent the window region.|
|Success:||Specifies the type of the region that the function obtains. It can be one of the following values
$NULLREGION - The region is empty.
$SIMPLEREGION - The region is a single rectangle.
$COMPLEXREGION - The region is more than one rectangle.
|Failure:||0 The specified window does not have a region, or an error occurred while attempting to return the region.|
The window region of a window is set by calling the SetWindowRgn function.
The window region determines the area within the window where the system permits drawing.
The system does not display any portion of a window that lies outside of the window region
The coordinates of a window's window region are relative to the upper-left corner of the window, not the client area of the window.
To set the window region of a window, call the SetWindowRgn function.
_WinAPI_CombineRgn, _WinAPI_CreateRectRgn, _WinAPI_CreateRoundRectRgn, _WinAPI_SetWindowRgn
Search GetWindowRgn in MSDN Library.