抓取屏幕并压缩生成HBITMAP

 HBITMAP GetScreenBmp()

 {

     HWND hwnd = ::GetDesktopWindow();

     HDC hsrc = ::GetDC(hwnd);

     HDC hmemdc = ::CreateCompatibleDC(hsrc);

     RECT rc; ::GetWindowRect(hwnd,&rc);

     SIZE sz;sz.cx=rc.right-rc.left;sz.cy=rc.bottom-rc.top;

     HBITMAP hbmp = ::CreateCompatibleBitmap(hsrc,sz.cx,sz.cy);

     HGDIOBJ holdbmp = ::SelectObject(hmemdc,hbmp);

     ::BitBlt(hmemdc,,,sz.cx,sz.cy,hsrc,rc.left,rc.top,SRCCOPY);

     ::SelectObject(hmemdc,holdbmp);

     ::DeleteObject(hmemdc);

     ::ReleaseDC(hwnd,hsrc);

     return hbmp;

 }