clipview.c

剪贴板编程的例子

/*-----------------------------------------
   CLIPVIEW.C -- Simple Clipboard Viewer
                 (c) Charles Petzold, 1996
  -----------------------------------------*/

#include <windows.h>

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
     {
     static char  szAppName[] = "ClipView" ;
     HWND         hwnd ;
     MSG          msg ;
     WNDCLASSEX   wndclass ;

     wndclass.cbSize        = sizeof (wndclass) ;
     wndclass.style         = CS_HREDRAW | CS_VREDRAW ;
     wndclass.lpfnWndProc   = WndProc ;
     wndclass.cbClsExtra    = 0 ;
     wndclass.cbWndExtra    = 0 ;
     wndclass.hInstance     = hInstance ;
     wndclass.hIcon         = NULL ;
     wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW) ;
     wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
     wndclass.lpszMenuName  = NULL ;
     wndclass.lpszClassName = szAppName ;
     wndclass.hIconSm       = LoadIcon (NULL, IDI_APPLICATION) ;

     RegisterClassEx (&wndclass) ;

     hwnd = CreateWindow (szAppName, "Simple Clipboard Viewer (Text Only)",
                          WS_OVERLAPPEDWINDOW,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          NULL, NULL, hInstance, NULL) ;

     ShowWindow (hwnd, iCmdShow) ;
     UpdateWindow (hwnd) ;

     while (GetMessage (&msg, NULL, 0, 0))
          {
          TranslateMessage (&msg) ;
          DispatchMessage (&msg) ;
          }
     return msg.wParam ;
     }

LRESULT CALLBACK WndProc (HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam)
     {
     static HWND hwndNextViewer ;
     HGLOBAL     hGMem ;
     HDC         hdc ;
     PSTR        pGMem ;
     PAINTSTRUCT ps ;
     RECT        rect ;

     switch (iMsg)
          {
          case WM_CREATE :
               hwndNextViewer = SetClipboardViewer (hwnd) ;
               return 0 ;

          case WM_CHANGECBCHAIN :
               if ((HWND) wParam == hwndNextViewer)
                    hwndNextViewer = (HWND) lParam ;

               else if (hwndNextViewer)
                    SendMessage (hwndNextViewer, iMsg, wParam, lParam) ;

               return 0 ;

          case WM_DRAWCLIPBOARD :
               if (hwndNextViewer)
                    SendMessage (hwndNextViewer, iMsg, wParam, lParam) ;

               InvalidateRect (hwnd, NULL, TRUE) ;
               return 0 ;

          case WM_PAINT :
               hdc = BeginPaint (hwnd, &ps) ;
               GetClientRect (hwnd, &rect) ;
               OpenClipboard (hwnd) ;

               hGMem = GetClipboardData (CF_TEXT) ;

               if (hGMem != NULL)
                    {
                    pGMem = (PSTR) GlobalLock (hGMem) ;
                    DrawText (hdc, pGMem, -1, &rect, DT_EXPANDTABS) ;
                    GlobalUnlock (hGMem) ;
                    }

               CloseClipboard () ;
               EndPaint (hwnd, &ps) ;
               return 0 ;

          case WM_DESTROY :
               ChangeClipboardChain (hwnd, hwndNextViewer) ;
               PostQuitMessage (0) ;
               return 0 ;
          }
     return DefWindowProc (hwnd, iMsg, wParam, lParam) ;
     }