MsMultiPartFormDataStream post表单出错


procedure TForm1.Button4Click(Sender: TObject);
var
 url,fankui: string;
 stream: TStringStream;
 data: TMsMultiPartFormDataStream;
 ResponseStream: TMemoryStream;
begin
 url:='http://127.0.0.1/dede/article_add.php';
 data := TMsMultiPartFormDataStream.Create;
 memo1.Clear;
 memo1.Lines.add(utf8encode((StripHTML(decontent)+depic+degmap)));
 //exit;
 stream:= TStringstream.Create('');
  ResponseStream := TMemoryStream.Create;
  try
    IdHttp1.Request.ContentType := data.RequestContentType;
    data.AddFormField('title', Utf8encode(detopic));
    data.AddFormField('body',Utf8encode(decontent));
    data.AddFormField('typeid','38');
    data.AddFormField('channelid','1');
     
    data.PrepareStreamForDispatch;
    data.Position := 0;
    IdHTTP1.Post(url, data, ResponseStream);
    responsestream.SaveToStream(stream);
    fankui:= utf8toansi(stream.DataString);
    memo1.Clear;
    Memo1.Lines.Add(fankui);
     
    finally
    data.Free;
    ResponseStream.Free;
  end;end;
decontent包含<div <img 等字符的时候，程序就出错，如下图
请问这个问题怎样解决呢？