The WM_PALETTEISCHANGING message informs applications that an application is going to realize its logical palette.
A window receives this message through its WindowProc function.
LRESULT CALLBACK WindowProc( HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam );
A handle to the window that is going to realize its logical palette.
This parameter is not used.
If an application processes this message, it should return zero.
The application changing its palette does not wait for acknowledgment of this message before changing the palette and sending the WM_PALETTECHANGED message. As a result, the palette may already be changed by the time an application receives this message.
If the application either ignores or fails to process this message and a second application realizes its palette while the first is using palette indexes, there is a strong possibility that the user will see unexpected colors during subsequent drawing operations.
|Minimum supported client
||Windows 2000 Professional [desktop apps only]
|Minimum supported server
||Windows 2000 Server [desktop apps only]