//下面代码显示了如何使用WM_ENDSESSION WM_DESTROY WM_QUIT消息,基本上来自于//<<win95-a-developers-guide>>的第一章
LRESULT WINAPI XXX_WndProc(HWND hwnd,UINT uMsg,WPARAM wParam,LPARAM lParam) ... { switch(uMsg)...{ HANDLE_MSG(hwnd,WM_CLOSE, xxx_OnClose); HANDLE_MSG(hwnd,WM_DESTROY, xxx_OnDestroy); HANDLE_MSG(hwnd,WM_QUERYENDSESSION, xxx_OnQueryEndSession); HANDLE_MSG(hwnd,WM_ENDSESSION, xxx_OnEndSession); } return( DefWindowProc(hwnd,uMsg,wParam,lParam));} BOOL xxx_OnQueryEndSession(HWND hwnd) ... { //For demonstration purpose ,pretend that there is unsaved data. BOOL fIsDataUnsaved = TRUE; BOOL fOkToEndSession = TRUE; if (fIsDataUnsaved) ...{ //Present message box. int n = MessageBox(hwnd,__TEXT("Do you want to save changes?"), __TEXT("xxx --Example technique for proper shutdown"), MB_YESNOCANCEL|MB_ICONWARNING); if(n == IDYES) ...{ //you would present a file save dialog box here. } if (n == IDCANCEL) fOkToEndSession = FALSE; } return(fOkToEndSession);} /**/ // void xxx_OnEndSession(HWND hwnd, BOOL fEnding) ... { if (fEnding) ...{ //if the session is really ending ,explicitly destroy the window. DestroyWindow(hwnd); //DestroyWindow will send WM_DESTROY and WM_NCDESTROY message. }} /**/ // void xxx_OnDestroy(HWND hwnd) ... { //the system will automaticllyu destory the edit child window. //the main window is being destroyed;signal the message loop to terminate //so that the thread and process terminate. PostQuitMessage(0);} /**/ // void xxx_OnClose(HWND hwnd) ... { // we handle WM_CLOSE the same way we would handle a logoff or shutdown. BOOL fOkToClose = xxx_OnQueryEndSession(hwnd); xxx_OnEndSession(hwnd,fOkToClose);} /**/ //
