远程屏幕抓在显示在IMAGE上是个完整的屏幕截图，但发送出去在服务端却只能显示其中的一部分？？

Question

程序如下：请教高手，帮忙看看哪里出了问题？？      
       ss:=tcanvas.Create;
       FStream:=TMemoryStream.Create;
       ss.Handle:=getdc(0);
       sb:=Tbitmap.Create;
       //sb.Width:=BMPINFO.bmiHeader.biWidth;
       //sb.height:=BMPINFO.bmiHeader.biHeight;
       sb.Width:=screen.Width;
       sb.Height:=screen.Height;
       sb.PixelFormat:=pf16bit;
       bitblt(sb.Canvas.Handle,0,0,sb.width,sb.height,ss.Handle,0,0,srccopy);
       sb.Canvas.CopyRect(Rect(0,0,screen.Width,screen.Height),ss,Rect(0,0,Screen.Width,Screen.Height));
       ss.Free;
       image1.Picture.Bitmap:=sb; //*******************
       image1.Width:=sb.Width;
       image1.Height:=sb.Height;       FormClient.WindowState:=wsNormal;
       FormClient.show;
       jpgstream:=TJPEGImage.Create;
       jpgstream.Assign(sb);
       jpgstream.CompressionQuality:=10; //  压缩质量
       jpgstream.JPEGNeeded;
       jpgstream.Compress;
       //FStream.CopyFrom(AData,AData.Size);
       jpgstream.SaveToStream(FStream);  //保存为JPG流************888888
       jpgstream.Free;
       //FStream.Position:=0; //******
       //因为UDP数据包有大小限制，这里如果超出部分，就没有传输，完全可以发几次发出去
  FormClient.IdUDPClient1.BroadcastEnabled:=true;//用广播功能  if FStream.Size>FormClient.IdUDPClient1.BufferSize then
    begin
      FormClient.IdUDPClient1.SendBuffer(IPAddr,port,FStream.Memory^,FormClient.IdUDPClient1.BufferSize);
    end
  else
    begin
      FormClient.IdUDPClient1.SendBuffer(IPAddr,port,FStream.Memory^,FormClient.IdUDPClient1.BufferSize);    end;
  FStream.Free;
  sb.Free;

Answer 1

现在好像是带宽的原因，如果把jpgstream.CompressionQuality:=10的值设的小点就会显示的多一些，目前发现

Answer 2

图像缩小：uses GdiPlus;
var
  n: Single = 0.75; {缩放倍数}
procedure TForm1.FormPaint(Sender: TObject);
var
  g: TGPGraphics;
  img: TGPImage;
  rt: TGPRectF;
begin
  g := TGPGraphics.Create(Self.Canvas.Handle);
  img := TGPImage.Create('C:\temp\test.png');  g.DrawImage(img, 4, 4, img.GetWidth, img.GetHeight);  rt := MakeRect(4+img.GetWidth+4, 4, img.GetWidth * n, img.GetHeight * n);  g.SetInterpolationMode(TInterpolationMode);
  g.DrawImage(img, rt, 0, 0, img.GetWidth, img.GetHeight, UnitPixel);  img.Free;
  g.Free;
end;
TInterpolationMode:
InterpolationModeInvalid             = -1; {等效于 QualityMode 枚举的 Invalid 元素. }
InterpolationModeDefault             = 0;  {指定默认模式. }
InterpolationModeLowQuality          = 1;  {指定低质量插值法. }
InterpolationModeHighQuality         = 2;  {指定高质量插值法. }
InterpolationModeBilinear            = 3;  {指定双线性插值法. 不进行预筛选. 将图像收缩为原始
                                                  大小的 50% 以下时，此模式不适用. }
InterpolationModeBicubic             = 4;  {指定双三次插值法. 不进行预筛选. 将图像收缩为原始
                                                  大小的 25% 以下时，此模式不适用. }
InterpolationModeNearestNeighbor     = 5;  {指定最临近插值法. }
InterpolationModeHighQualityBilinear = 6;  {指定高质量的双线性插值法. 执行预筛选以确保高质量
                                                  的收缩.  }
InterpolationModeHighQualityBicubic  = 7;  {指定高质量的双三次插值法. 执行预筛选以确保高质量
                                                  的收缩. 此模式可产生质量最高的转换图像. }摘自：http://www.cnblogs.com/del/archive/2008/07/03/1234641.html

Answer 3

有源码自己去看看
http://iamgyg.blog.163.com/