Sent to an application when the IME changes composition status as a result of a keystroke. A window receives this message through its WindowProc function.
LRESULT CALLBACK WindowProc( HWND hwnd, WM_IME_COMPOSITION, WPARAM wParam, LPARAM lParam );
A handle to window.
DBCS character representing the latest change to the composition string.
Value specifying how the composition string or character changed. This parameter can be one or more of the following values. For more information about these values, see IME Composition String Values.
The lParam parameter can also have one or more of the following values.
This message has no return value.
An application should process this message if it displays composition characters itself. Otherwise, it should send the message to the IME window.
If the application has created an IME window, it should pass this message to that window. The DefWindowProc function processes this message by passing it to the default IME window. The IME window processes this message by updating its appearance based on the change flag specified. An application can call ImmGetCompositionString to retrieve the new composition status.
If none of the GCS_ values are set, the message indicates that the current composition has been canceled and applications that draw the composition string should delete the string.
Minimum supported client
|Windows 2000 Professional [desktop apps only]|
Minimum supported server
|Windows 2000 Server [desktop apps only]|
Build date: 11/16/2013