| SetWindowRgn(IntPtr, IntPtr, Boolean) | Sets the window region of a window. 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 |
| SetWindowRgn(SafeHandle, SafeHandle, Boolean) | Sets the window region of a window. 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 |