用IdHTTP控件下载


procedure TForm1.DownLoadFile(URL:String;FileName:String;Resume:Boolean);
var
  tStream : TFileStream ;
begin
  if FileExists(FileName) then
      tStream := TFileStream.Create(FileName,fmOpenReadWrite)
  else
      tStream := TFileStream.Create(FileName,fmCreate);  if Resume then  //断点续传
  begin
    IdHttp1.Request.ContentRangeStart := tStream.Size - 1 ;
    tStream.Position := tStream.Size - 1 ;
    IdHttp1.Head(URL);
    IdHttp1.Request.ContentRangeEnd := IdHttp1.Response.ContentLength ;
  end
  else
    IdHttp1.Request.ContentRangeStart := 0 ;  try
    IdHttp1.Get(URL,tStream);
  finally
    tStream.Free ;
  end;end;procedure TForm1.Button2Click(Sender: TObject);
begin
  DownLoadFile('http://10.136.72.121:2000/updateimage/renderingsimages/0000000001/','O1016448851703512.jpg',false);
end;
不知道还需要设置什么，我现在的问题是下了2K就没反应了？？？？