| UpdateWindow(IntPtr) | Updates the client area of the specified window by sending a WM_Paint message to the window if the window's update region is not empty. The function sends a WM_Paint message directly to the window procedure of the specified window, bypassing the application queue. If the update region is empty, no message is sent. |
| UpdateWindow(SafeHandle) | Updates the client area of the specified window by sending a WM_Paint message to the window if the window's update region is not empty. The function sends a WM_Paint message directly to the window procedure of the specified window, bypassing the application queue. If the update region is empty, no message is sent. |