CAsyncSocket::OnConnect

Статья
10/16/2008

Called by the framework to notify this connecting socket that its connection attempt is completed, whether successfully or in error.

virtual void OnConnect(
   int nErrorCode 
);

Параметры

nErrorCode
The most recent error on a socket. The following error codes apply to the OnConnect member function:
- 0 The function executed successfully.
- WSAEADDRINUSE The specified address is already in use.
- WSAEADDRNOTAVAIL The specified address is not available from the local machine.
- WSAEAFNOSUPPORT Addresses in the specified family cannot be used with this socket.
- WSAECONNREFUSED The attempt to connect was forcefully rejected.
- WSAEDESTADDRREQ A destination address is required.
- WSAEFAULT The lpSockAddrLen argument is incorrect.
- WSAEINVAL The socket is already bound to an address.
- WSAEISCONN The socket is already connected.
- WSAEMFILE No more file descriptors are available.
- WSAENETUNREACH The network cannot be reached from this host at this time.
- WSAENOBUFS No buffer space is available. The socket cannot be connected.
- WSAENOTCONN The socket is not connected.
- WSAENOTSOCK The descriptor is a file, not a socket.
- WSAETIMEDOUT The attempt to connect timed out without establishing a connection.

Заметки

Примечание.
In CSocket, the OnConnect notification function is never called. For connections, you simply call Connect, which will return when the connection is completed (either successfully or in error). How connection notifications are handled is an MFC implementation detail.

For more information, see Windows Sockets: Socket Notifications.

Пример

void CMyAsyncSocket::OnConnect(int nErrorCode)   // CMyAsyncSocket is 
                                                 // derived from CAsyncSocket
{
   if (0 != nErrorCode)
   {
      switch(nErrorCode)
      {
         case WSAEADDRINUSE: 
            AfxMessageBox(_T("The specified address is already in use.\n"));
            break;
         case WSAEADDRNOTAVAIL: 
            AfxMessageBox(_T("The specified address is not available from ")
            _T("the local machine.\n"));
            break;
         case WSAEAFNOSUPPORT: 
            AfxMessageBox(_T("Addresses in the specified family cannot be ")
            _T("used with this socket.\n"));
            break;
         case WSAECONNREFUSED: 
            AfxMessageBox(_T("The attempt to connect was forcefully rejected.\n"));
            break;
         case WSAEDESTADDRREQ: 
            AfxMessageBox(_T("A destination address is required.\n"));
            break;
         case WSAEFAULT: 
            AfxMessageBox(_T("The lpSockAddrLen argument is incorrect.\n"));
            break;
         case WSAEINVAL: 
            AfxMessageBox(_T("The socket is already bound to an address.\n"));
            break;
         case WSAEISCONN: 
            AfxMessageBox(_T("The socket is already connected.\n"));
            break;
         case WSAEMFILE: 
            AfxMessageBox(_T("No more file descriptors are available.\n"));
            break;
         case WSAENETUNREACH: 
            AfxMessageBox(_T("The network cannot be reached from this host ")
            _T("at this time.\n"));
            break;
         case WSAENOBUFS: 
            AfxMessageBox(_T("No buffer space is available. The socket ")
               _T("cannot be connected.\n"));
            break;
         case WSAENOTCONN: 
            AfxMessageBox(_T("The socket is not connected.\n"));
            break;
         case WSAENOTSOCK: 
            AfxMessageBox(_T("The descriptor is a file, not a socket.\n"));
            break;
         case WSAETIMEDOUT: 
            AfxMessageBox(_T("The attempt to connect timed out without ")
               _T("establishing a connection. \n"));
            break;
         default:
            TCHAR szError[256];
            _stprintf_s(szError, _T("OnConnect error: %d"), nErrorCode);
            AfxMessageBox(szError);
            break;
      }
      AfxMessageBox(_T("Please close the application"));
   }
   CAsyncSocket::OnConnect(nErrorCode);
}