TMemo 循环获取某一行值新方法

procedure TfrmFilterTopTidByTopOutSidList.Button1Click(Sender: TObject);
var
  I: Integer;
  top_out_sid_list_str: string;
begin
  top_out_sid_list_str := '';
  ShowMessage(IntToStr(TopOutSidList_mmo.Lines.Count));
  for I := 0 to TopOutSidList_mmo.Lines.Count - 1 do
  begin
    if I <> 0 then
    begin
      top_out_sid_list_str := top_out_sid_list_str + ',' + TopOutSidList_mmo.Lines.Strings[I];
    end else begin
      top_out_sid_list_str := TopOutSidList_mmo.Lines.Strings[I];
    end;
  end;
  ShowMessage(top_out_sid_list_str);
end;

TopOutSidList_mmo.Lines.Strings[I];