【Delphi】indy10下 utf8码转换的问题

procedure Download(Url: String);
var
  Sstr   : TStringStream;
  Idhttp : TIdHTTP;
begin
  Idhttp := TIdHTTP.Create(nil);
  Sstr   := TStringStream.Create('', TEncoding.GetEncoding(65001)); {指定gb2312的中文代码页,或者54936(gb18030)更好些utf8对应65001}
  Idhttp.Get(Url, Sstr);
  {
  ..............
  ..............
  ..............
  }