class MyApp extends StatefulWidget {
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  MyBloc _myBloc;
  
  @override
  initState() {
    super.initState();
    _myBloc = MyBloc();
  }

  @override
  Widget build(BuildContext context) {
    return BlocProvider(
      bloc: _myBloc,
      child: MyPage(),
    );
  }

  @override
  dispose() {
    _myBloc.dispose();
    super.dispose();
  }
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return BlocProvider(
      builder: (BuildContext context) => MyBloc(),
      dispose: (BuildContext context, MyBloc bloc) => bloc.dispose(),
      child: MyPage(),
    );
  }
}