VC中WM_CLOSE、WM_DESTROY、WM_QUIT消息出现顺序及调用方式

VC中WM_CLOSE、WM_DESTROY、WM_QUIT消息出现顺序及调用方式wxleasyland@2012.7wxleasyland试验：一、VC建的标准WIN32－HELLO WORLD程序中，case WM_DESTROY://PostQuitMessage(0);将这行屏蔽则，点关闭，窗口关闭了，但是程序进程还在！要在任务管理器中中止。

二、VC建的标准WIN32－HELLO WORLD程序中，1. 在WndProc()中加上case WM_CLOSE:WinExec("cmd /k echo WM_CLOSE: ",SW_SHOW);break;2. 按右上角的X、点图标\关闭、或者按ALT+F4，都只出现cmd窗，不会关闭程序。

因为原来是执行default: return DefWindowProc(hWnd, message, wParam, lParam); 即DefWindowProc来处理WM_CLOSE消息。

现在被case WM_CLOSE:拦截了。

3. 点菜单里的FILE\EXIT，则就是执行case WM_COMMAND: 里的case IDM_EXIT:DestroyWindow(hWnd); 了。

不会执行case WM_CLOSE:！！！DestroyWindow(hWnd); 会销毁窗口，同时发送WM_DESTROY消息直接让WndProc()处理（不经过消息队列）。

三、VC建的标准WIN32－HELLO WORLD程序中，1. 在WndProc()中加上case WM_CLOSE:WinExec("cmd /k echo WM_CLOSE: ",SW_SHOW);return DefWindowProc(hWnd, message, wParam, lParam);break;case WM_DESTROY:WinExec("cmd /k echo WM_DESTROY: ",SW_SHOW);PostQuitMessage(0);break;2. 按右上角的X、点图标\关闭、或者按ALT+F4，会先出现WM_CLOSE，再出现WM_DESTROY。

3. 点菜单里的FILE\EXIT，则只出现WM_DESTROY。

四、VC建的标准WIN32－HELLO WORLD程序中，如果用PostQuitMessage(0); 则不出现WM_CLOSE。

也不会出现WM_DESTROY！！！！！！！窗口会关闭，程序退出。

这应该是正常的，WM_QUIT让GetMessage()为0，从而WinMain()退出，然后操作系统会自动去销毁窗口。

主程序已经没了，所以即使WM_DESTROY出现了也没用。

经试，在PostQuitMessage(0);后面的语句会继续执行到完。

PostQuitMessage只是产生一个WM_QUIT 消息到消息队列中并马上返回。

所以标准WIN32程序是：按右上角的X->出现WM_CLOSE退出菜单点EXIT->出现运行五、在MFC对话框程序中，试验，是：1. 先WM_CLOSE（这时窗口仍在显示）－>再WM_DESTROY（窗口已经消失）－>OnDestroy()执行完后，程序完全退出2. WM_CLOSE不一定会出现。

WM_CLOSE 点右上角的X，点图标\关闭，或者按ALT+F4，会出现。

点OK按钮、或者Cancle按钮，或者用任务管理器强行中止，都不会出现。

3. WM_DESTROY 点右上角的X，点OK按钮、或者Cancle按钮，都会出现。

而且晚于WM_CLOSE 出现。

用任务管理器强行中止，则不会出现。

4. 如果在程序中按一个按钮，里有PostQuitMessage(0); 则不出现WM_CLOSE，但会出现WM_DESTROY，窗口会关闭，程序退出。

经试，按钮函数里，在PostQuitMessage(0);后面的语句会继续执行到完。

PostQuitMessage只是产生一个WM_QUIT消息到消息队列中并马上返回。

5. 如果在程序中按一个按钮，里有PostMessage(WM_DESTROY); 则不出现WM_CLOSE，但会出现WM_DESTROY。

窗口不会关闭，还能正常用。

所以MFC对话框程序是：按右上角的X->出现WM_CLOSE->产生WM_DESTROY ->OnDestroy()执行完后程序退出点确认或取消按钮运行＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝h p://m s d n.m i c ro s o .co m/e n-us/l i b rary/w i n d ow s/d es ktop/m s632617(v=vs.85).a s pxWM_CLOSE messageSent as a signal that a window or an application should terminate.A window receives this message through its WindowProc function. 窗口通过WindowProc函数来接收这个消息！An application can prompt the user for confirmation, prior to destroying a window, by processing the WM_CLOSE message and calling the DestroyWindow function only if the user confirms the choice. 程序中可以让用户确认是否真的要退出。

By default, the DefWindowProc function calls the DestroyWindow function to destroy the window.WM_DESTROY messageSent when a window is being destroyed.It is sent to the window procedure of the window being destroyed after the window is removed from the screen. 当窗口被从屏幕上删除掉之后，这个消息才被发送给窗口程序。

This message is sent first to the window being destroyed and then to the child windows (if any) as they are destroyed. During the processing of the message, it can be assumed that all child windows still exist. 在处理消息的过程中，所有子窗仍然存在。

A window receives this message through its WindowProc function. 窗口通过WindowProc函数来接收这个消息！If the window being destroyed is part of the clipboard viewer chain (set by calling the SetClipboardViewer function), the window must remove itself from the chain by processing the ChangeClipboardChain function before returning from the WM_DESTROY message.WM_NCDESTROY messageNotifies a window that its nonclient area is being destroyed.The DestroyWindow function sends the WM_NCDESTROY message to the window following the WM_DESTROY message. WM_NCDESTROY是在WM_DESTROY消息之后。

WM_DESTROY is used to free the allocated memory object associated with the window.The WM_NCDESTROY message is sent after the child windows have been destroyed. In contrast, WM_DESTROY is sent before the child windows are destroyed.A window receives this message through its WindowProc function. 窗口通过WindowProc函数来接收这个消息！This message frees any memory internally allocated for the window.WM_QUIT messageIndicates a request to terminate an application, and is generated when the application calls the PostQuitMessage function. This message causes the GetMessage function to return zero.The WM_QUIT message is not associated with a window and therefore will never be received through a window's window procedure. WM_QUIT消息与窗口没有关联，所以窗口处理程序收不到这个消息。

It is retrieved only by the GetMessage or PeekMessage functions.Do not post the WM_QUIT message using the PostMessage function; use PostQuitMessage.PostQuitMessage functionIndicates to the system that a thread has made a request to terminate (quit). It is typically used in response to a WM_DESTROY message.The PostQuitMessage function posts a WM_QUIT message to the thread's message queue and returns immediately; PostQuitMessage只是产生一个WM_QUIT消息到线程的消息队列中并马上返回。