The SendAsyncProc function is an application-defined callback function used with the SendMessageCallback function. The system passes the message to the callback function after passing the message to the destination window procedure. The SENDASYNCPROC type defines a pointer to this callback function. SendAsyncProc is a placeholder for the application-defined function name.
VOID CALLBACK SendAsyncProc(
HWND hwnd, // handle of destination window
UINT uMsg, // message
DWORD dwData, // application-defined value
LRESULT lResult // result of message processing
);
If the SendMessageCallback function was called with its hwnd parameter set to HWND_BROADCAST, the system calls the SendAsyncProc function once for each top-level window.
This callback function does not return a value.
You install a SendAsyncProc application-defined callback function by passing a SENDASYNCPROC pointer to the SendMessageCallback function.
The callback function is only called when the thread that called SendMessageCallback calls GetMessage, PeekMessage, or WaitMessage.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in winuser.h.
Import Library: User-defined.
Messages and Message Queues Overview, Message and Message Queue Functions, GetMessage, PeekMessage, SendMessageCallback, WaitMessage