问windows - sendmessage

EN

HWND hwnd; 
BOOL fDone; 
MSG msg; 

// Begin the operation and continue until it is complete 
// or until the user clicks the mouse or presses a key. 

fDone = FALSE; 
while (!fDone) 
{ 
    fDone = DoLengthyOperation(); // application-defined function 

    // Remove any messages that may be in the queue. If the 
    // queue contains any mouse or keyboard 
    // messages, end the operation. 

    while (PeekMessage(&msg, hwnd,  0, 0, PM_REMOVE)) 
    { 
        switch(msg.message) 
        { 
            case WM_LBUTTONDOWN: 
            case WM_RBUTTONDOWN: 
            case WM_KEYDOWN: 
                // 
                // Perform any required cleanup. 
                // 
                fDone = TRUE; 
        } 
    } 
}