[Flutter]GridView

下面代碼為兩列的GridView

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new GridView.count(
      crossAxisCount: 2,
      children: new List.generate(20, (index) {
        return new Center(
          child: new Text(
            '$index',
          ),
        );
      }),
    );
  }
}