Widget Stateful
flutter run --no-sound-null-safety
Zion
flutter run --no-sound-null-safetyclass YellowBird extends StatefulWidget {
const YellowBird({ Key key }) : super(key: key);
@override
_YellowBirdState createState() => _YellowBirdState();
}
class _YellowBirdState extends State<YellowBird> {
@override
Widget build(BuildContext context) {
return Container(color: const Color(0xFFFFE306));
}
}