VB不允许退出Windows的程序源代码，设置了允许退出和不允许退出两种功能。记录Window Procedure的地址，开始截取消息,并将消息交给wndproc过程处理.取消消息截取，结束子分类过程.

　　本函数就是用来接收子分类时截取的消息的

　　Public Function wndproc(ByVal hwnd As Long, ByVal Msg As Long, _

　　 ByVal wParam As Long, ByVal lParam As Long) As Long

　　 截取下来的消息存放在msg参数中.

　　 If (Msg = WM_QUERYENDSESSION) And (m_AllowExit = False) Then

　　 检测到消息,这里就可以加入处理代码

　　 需要注意,如果这儿不加入任何代码,则相当于吃掉了这条消息.

　　 Else

　　 如果不是需要处理的消息,则将之送回原来的程序.

　　 wndproc = CallWindowProc(preWinProc, hwnd, Msg, wParam, lParam)

　　 End If

　　End Function-VB is not allowed to exit the Windows source code, set up to allow exit and allowed to exit the two functions. Record Window Procedure of the address to begin the interception of messages and message handling process to wndproc Cancel message interception, ending the sub classification process. This function is receiving sub-categories intercepted message to the Public Function wndproc (ByVal hwnd As Long, ByVal Msg As Long, _ ByVal wParam As Long, ByVal lParam As Long) As Long ' interception down the message stored in the msg parameter. If (Msg = WM_QUERYENDSESSION) And (m_AllowExit = False) Then'　message is detected, where you can adding processing code ' need attention, if not join any code here, then ate the equivalent of this message. Else'　message if it is not to be processed, then sent back to the original program. wndproc = CallWindowProc (preWinProc, hwnd, Msg, wParam, lParam) End If End Function