hWndC := capCreateCaptureWindowA('教师资格照片采集',WS_CHILD or WS_VISIBLE ,Panel1.Left+5,Panel1.Top+5,640,480,Form1.Handle,0);

//显示的视频在Panel1控件上，并调整好视频大小和位置

if hWndC <> 0 then

SendMessage(hWndC, WM_CAP_SET_CALLBACK_VIDEOSTREAM, 0, 0);

SendMessage(hWndC, WM_CAP_SET_CALLBACK_ERROR, 0, 0);

SendMessage(hWndC, WM_CAP_SET_CALLBACK_STATUSA, 0, 0);

SendMessage(hWndC, WM_CAP_DRIVER_CONNECT, 0, 0);

SendMessage(hWndC, WM_CAP_SET_SCALE, 1, 0);

SendMessage(hWndC, WM_CAP_SET_PREVIEWRATE, 66, 0);

SendMessage(hWndC, WM_CAP_SET_OVERLAY, 1, 0);

SendMessage(hWndC, WM_CAP_SET_PREVIEW, 1, 0);

end;

2.2  截取整幅图像

截取整幅图像保存成一个BMP文件，并通过Image控件显示出来：

　　　　procedure TForm1.Button1Click(Sender: TObject);

var

  bakrec:TRect;

begin

     if hWndC<>0 then

     begin

          if pregrab then

             begin

             SendMessage(hWndc,WM_CAP_SET_PREVIEWRATE,30,0) ;

SendMessage(hWndc,WM_CAP_SET_PREVIEW,WPARAM(true),0);

             pregrab:=false;

             end

          else