程序池ProcessRequest问题,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

procedure TfrmTest.ProcessRequest(Sender: TCnThreadPool;
  aDataObj: TCnTaskDataObject; aThread: TCnPoolingThread);
var
  d: TSendData;
  t: TSendThread;
begin
  d := TSendData(aDataObj);
  t := TSendThread(aThread);
  if (d = nil) or (t = nil) then
    Exit;
  Inc(ProcessCount);
  try
    t.idhttp1.Head(d.FMsg);//编译无错,但是跑到这一步就except了,请问怎么弄
    sReadln:=t.idhttp1.Response.RawHeaders.ValueFromIndex[1];
    t.Synchronize(Updatemmo1);   
  except
  end;
end;