Widget _centerTable(BuildContext context) {
    return TDTable(
      columns: [
        TDTableCol(title: '标题', colKey: 'title1', align: TDTableColAlign.center),
        TDTableCol(title: '标题', colKey: 'title2', align: TDTableColAlign.center),
        TDTableCol(title: '标题', colKey: 'title3', align: TDTableColAlign.center),
        TDTableCol(title: '标题', colKey: 'title4', align: TDTableColAlign.center)
      ],
      data: _getData(10),
    );
  }