The UpdateWindow function 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.
BOOL UpdateWindow(
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HWND hWnd |
// handle of window |
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); |
If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.
ExcludeUpdateRgn, GetUpdateRect, GetUpdateRgn, InvalidateRect, InvalidateRgn, WM_PAINT