BOOL ImeProcessKey (HIMC hIMC, UINT uVirKey, DWORD lParam,
CONST LPBYTE lpbKeyState)
Preprocesses keystrokes given through IMM.
The return value is TRUE if a key is necessary for the IME with the given input context. Otherwise, it is FALSE.
The system determines a key is handled by the IME by calling this function. When the function returns TRUE, the IME processes the key message before it is passed to an application. The system also calls the ImeToAsciiEx function. The function returns FALSE if the IME does not handle the key, in which case the system sends the key message to the target application.