WM_IME_KEYDOWN / WM_IME_KEYUP

The WM_IME_KEYDOWN / WM_IME_KEYUP message is sent to an application when the IME needs to generate a WM_KEYDOWN or WM_KEYUP message. The form of the value to be sent is the same as the original English Windows WM_KEYDOWN and WM_KEYUP messages.

There is no return value.

wParam

Same as the English Windows WM_KEYDOWN or WM_KEYUP.

lParam

Same as the English Windows WM_KEYDOWN or WM_KEYUP.

An application can handle these messages in the same way it handles the WM_KEYDOWN and WM_KEYUP messages. It can pass these messages to DefWindowProc to generate WM_KEYDOWN and WM_KEYUP messages with the same wParam and lParam parameters. This message is usually generated by the IME to maintain message order.