23. 领略internet.txt

本书介绍了在Microsoft Windows 98、Microsoft Windows NT 4.0和Windows NT 5.0下程序写作的方法

                return TRUE ;
        
                 }
        

                // Call "connect" with IP address and time-server port
        

                  sa.sin_family           = AF_INET ;
        
                  sa.sin_port             = htons (IPPORT_TIMESERVER) ;
        
                  sa.sin_addr.S_un.S_addr = inet_addr (szIPAddr) ;
        

                  connect(sock, (SOCKADDR *) &sa, sizeof (sa)) ;
        

              // "connect" will return SOCKET_ERROR because even if it
        
              // succeeds, it will require blocking. The following only
        
              // reports unexpected errors.
        

              if (WSAEWOULDBLOCK != (iError = WSAGetLastError ()))
        
                  {
        
              EditPrintf (hwndEdit, TEXT ("Connect error #%i.\r\n"), iError) ;
        
                          closesocket (sock) ;
        
                          WSACleanup () ;
        
                         return TRUE ;
        
              }
        
              EditPrintf (hwndEdit, TEXT ("Connecting to %hs..."), szIPAddr) ;
        
   
        
              // The result of the "connect" call will be reported
        
              // through the WM_SOCKET_NOTIFY message.
        
              // Set timer and change the button to "Cancel"
        

             SetTimer (hwnd, ID_TIMER, 1000, NULL) ;
        
             GetWindowText (hwndButton, szOKLabel, sizeof (szOKLabel) /sizeof (TCHAR)) ;
        
             SetWindowText (hwndButton, TEXT ("Cancel")) ;
        
             SetWindowLong (hwndButton, GWL_ID, IDCANCEL) ;
        
            return TRUE ;
        

                          case   IDCANCEL:
        
                                                 closesocket (sock) ;
        
                                                 sock = 0 ;
        
                                                 WSACleanup () ;
        
                                                 SetWindowText (hwndButton, szOKLabel) ;
        
                                                SetWindowLong (hwndButton, GWL_ID, IDOK) ;
        

                                                 KillTimer (hwnd, ID_TIMER) ;
        
                                                 EditPrintf (hwndEdit, TEXT ("\r\nSocket closed.\r\n")) ;
        
                                                 return TRUE ;
        

                          case   IDC_CLOSE:
        
                                        if (sock)
        
                          SendMessage (hwnd, WM_COMMAND, IDCANCEL, 0) ;
        

                                                 DestroyWindow (GetParent (hwnd)) ;
        
                                                 return TRUE ;
        
                          }
        
                          return FALSE ;
        

           case   WM_TIMER:
        
                          EditPrintf (hwndEdit, TEXT (".")) ;
        
                          return TRUE ;
        

           case   WM_SOCKET_NOTIFY:
        
                          wEvent = WSAGETSELECTEVENT (lParam) ;   // ie, LOWORD
        
                          wError = WSAGETSELECTERROR (lParam) ;   // ie, HIWORD
        

                                         // Process two events specified in WSAAsyncSelect
        

                          switch (wEvent)
        
                          {
        
       // This event occurs as a result of the "connect" call
        

                          case   FD_CONNECT:
        
                                                 EditPrintf (hwndEdit, TEXT ("\r\n")) ;
        

                                               if (wError)
        
                                                 {
        
      EditPrintf (hwndEdit, TEXT ("Connect error #%i."), wError) ;
        
      SendMessage (hwnd, WM_COMMAND, IDCANCEL, 0) ;
        
     return TRUE ;
        
          }
        
       EditPrintf (hwndEdit, TEXT ("Connected to %hs.\r\n"), szIPAddr) ;
        

        // Try to receive data. The call will generate an error
        
        // of WSAEWOULDBLOCK and an event of FD_READ
        

        recv (sock, (char *) &ulTime, 4, MSG_PEEK) ;
        
        EditPrintf (hwndEdit, TEXT ("Waiting to receive...")) ;
        
       return TRUE ;
        

        // This even occurs when the "recv" call can be made
        
             
        
                   case   FD_READ:
        
                                                 KillTimer (hwnd, ID_TIMER) ;
        
                                                 EditPrintf (hwndEdit, TEXT ("\r\n")) ;
        

                                                 if (wError)
        
                                                 {
        
       EditPrintf (hwndEdit, TEXT ("FD_READ error #%i."), wError) ;
        
       SendMessage (hwnd, WM_COMMAND, IDCANCEL, 0) ;
        
       return TRUE ;
        
       }
        
                                                 // Get the time and swap the bytes
        

         iSize = recv (sock, (char *) &ulTime, 4, 0) ;
        
         ulTime = ntohl (ulTime) ;
        
         EditPrintf (hwndEdit,
        
         TEXT ("Received current time of %u seconds ")
        
         TEXT ("since Jan. 1 1900.\r\n"), ulTime) ;
        

         // Change the system time
        
   
        
                                                 ChangeSystemTime (hwndEdit, ulTime) ;
        
                                                SendMessage (hwnd, WM_COMMAND, IDCANCEL, 0) ;
        
                                                 return TRUE ;
        
                          }
        
                          return FALSE ;
        
           }
        
           return FALSE ;
        
}
        

BOOL CALLBACK ServerDlg (  HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
        
{
        
           static char * szServer ;
        
           static WORD           wServer = IDC_SERVER1 ;
        
           char                                         szLabel [64] ;
        

           switch (message)
        
           {
        
           case   WM_INITDIALOG:
        
                         szServer = (char *) lParam ;
        
                          CheckRadioButton (hwnd, IDC_SERVER1, IDC_SERVER10, wServer) ;
        
                          return TRUE ;
        

           case   WM_COMMAND:
        
                          switch (LOWORD (wParam))
        
                          {
        
                          case   IDC_SERVER1:
        
                          case   IDC_SERVER2:
        
                          case   IDC_SERVER3:
        
                          case   IDC_SERVER4:
        
                          case   IDC_SERVER5:
        
                          case   IDC_SERVER6:
        
                          case   IDC_SERVER7:
        
                          case   IDC_SERVER8:
        
                          case   IDC_SERVER9:
        
                          case   IDC_SERVER10:
        
                                                 wServer = LOWORD (wParam) ;
        
                                                 return TRUE ;
        

                         case   IDOK:
        
                                                 GetDlgItemTextA (hwnd, wServer, szLabel, sizeof (szLabel)) ;
        
                                                 strtok (szLabel, "(") ;
        
                                                 strcpy (szServer, strtok (NULL, ")")) ;
        
                                                 EndDialog (hwnd, TRUE) ;
        
                                                return TRUE ;
        

                          case   IDCANCEL:
        
                                                 EndDialog (hwnd, FALSE) ;
        
                                                 return TRUE ;
        
                         }
        
                          break ;
        
   }
        
           return FALSE ;
        
}
        

void ChangeSystemTime (HWND hwndEdit, ULONG ulTime)
        
{
        
           FILETIME                            ftNew ;
        
           LARGE_INTEGER         li ;
        
           SYSTEMTIME                    stOld, stNew ;
        

           GetLocalTime (&stOld) ;
        
           stNew.wYear                                                 = 1900 ;
        
           stNew.wMonth                                         = 1 ;
        
           stNew.wDay                                           = 1 ;
        
           stNew.wHour                                          = 0 ;
        
           stNew.wMinute                                        = 0 ;
        
           stNew.wSecond                                        = 0 ;
        
           stNew.wMilliseconds                  = 0 ;
        

           SystemTimeToFileTime (&stNew, &ftNew) ;
        
           li = * (LARGE_INTEGER *) &ftNew ;
        
           li.QuadPart += (LONGLONG) 10000000 * ulTime ;
        
           ftNew = * (FILETIME *) &li ;
        
           FileTimeToSystemTime (&ftNew, &stNew) ;
        

           if (SetSystemTime (&stNew))
        
           {
        
                 GetLocalTime (&stNew) ;
        
                  FormatUpdatedTime (hwndEdit, &stOld, &stNew) ;
        
   }