Flutter: OrientationBuilder 根据方向更新UI

• 文档
• api

class _HomePageState extends State<HomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('根据方向更新UI'),
      ),
      body: OrientationBuilder(
        /// 构建可依赖于父窗口小部件方向的窗口小部件树（与设备方向MediaQuery.of(context).orientation不同）
        builder: (context, orientation) => GridView.count(
              crossAxisCount: orientation == Orientation.portrait ? 2 : 3,
              children: List.generate(
                  100, (index) => Center(child: Text('Item $index'))),
            ),
      ),
    );
  }
}