flutter when text set maxline and chinese in GridView it will incomplete display

this is my code.when i test it,the second line in text will incomplete display.like this

Widget testText() {
  return GridView.builder(
    scrollDirection: Axis.horizontal,
    gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 2),
    itemCount: 8,
    itemBuilder: (BuildContext context, int index) {
      return Text(
        '测试两行测试两行测测试两行试两行测测试两行试两',
        maxLines: 2,
        overflow: TextOverflow.ellipsis,
        style: TextStyle(fontSize: 20),
      );
    },
  );
}