platform.dart

class PlatformSwitch extends StatefulWidget {
  PlatformSwitch();
  
  @override
  _PlatformSwitchState createState() => _PlatformSwitchState();
}

class _PlatformSwitchState extends State<PlatformSwitch> {
  bool _value = false;
  
  @override
  Widget build(BuildContext context) {
    if (Platform.isIOS) {
      return CupertinoSwitch(value: _value, onChanged: onChanged);
    }
    return Switch(value: _value, onChanged: onChanged);
  }
  
  onChanged(bool value) {
    setState(() {
      _value = value;
    });
  }
}

매번 분기처리 하는것이 맘에 들지 않는다면!!

https://pub.dev/packages/flutter_platform_widgets 를 사용하자!