e、Switch开关主键

Switch 开关主键

 

class SwitchPage extends StatefulWidget {
  const SwitchPage({super.key});
  @override
  State<SwitchPage> createState() => _SwitchPageState();
}

class _SwitchPageState extends State<SwitchPage> {
  late bool flag = true; //注意这个的位置
  @override
  Widget build(BuildContext context) {
    return Scaffold(
 
      body: Center(
        child: Column(
          children: [
            Switch(
              value: flag,
              onChanged: (v) {
                setState(() {
                  flag = v;
                  print(v);
                });
              },
            )
          ],
        ),
      ),
    );
  }
}