问如何在热重新加载时使用Provider维护颤动全局BloC状态？

EN

abstract class BlocBase {
  void dispose();
}

class BlocProvider<T extends BlocBase> extends StatefulWidget {
  BlocProvider({
    Key key,
    @required this.child,
    @required this.bloc,
  }): super(key: key);

  final T bloc;
  final Widget child;

  @override
  _BlocProviderState<T> createState() => _BlocProviderState<T>();

  static T of<T extends BlocBase>(BuildContext context){
    final type = _typeOf<BlocProvider<T>>();
    BlocProvider<T> provider = context.ancestorWidgetOfExactType(type);
    return provider.bloc;
  }

  static Type _typeOf<T>() => T;
}

class _BlocProviderState<T> extends State<BlocProvider<BlocBase>>{
  @override
  void dispose(){
    widget.bloc.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context){
    return widget.child;
  }
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return BlocProvider<ApplicationStateBloc>(
      bloc: ApplicationStateBloc(),
      child: MaterialApp(
        title: 'Handshake',
        theme: ThemeData(
          primarySwatch: Colors.blue,
        ),
        home: LoadingPage(),
      )
    );
  }
}

class ProfileSettings extends StatefulWidget {
  @override
  _ProfileSettingsState createState() => _ProfileSettingsState();
}

class _ProfileSettingsState extends State<ProfileSettings>{
  ApplicationStateBloc _applicationStateBloc;

  @override
  void initState() {
    super.initState();
    _applicationStateBloc = BlocProvider.of<ApplicationStateBloc>(context);
  }

  @override
  void dispose() {
    _applicationStateBloc?.dispose();
    super.dispose();
  }

  Widget emailField() {
    return StreamBuilder<UserAccount>(
      stream: _applicationStateBloc.getUserAccount,
      builder: (context, snapshot){
        if (snapshot.hasData) {
          return Text(snapshot.data.displayName, style: TextStyle(color: Color(0xFF151515), fontSize: 16.0),);
        }
        return Text('');
      },
    );
  }

  @override
  Widget build(BuildContext context) {

    return BlocProvider<ApplicationStateBloc>(
      bloc: _applicationStateBloc,
      child: Scaffold(
        backgroundColor: Colors.white,
        body: SafeArea(
          child: Column(
            children: <Widget>[
              emailField(),
              .... // rest of code

class ApplicationStateBloc extends BlocBase {

  var userAccountController = BehaviorSubject<UserAccount>();
  Function(UserAccount) get updateUserAccount => userAccountController.sink.add;
  Stream<UserAccount> get getUserAccount => userAccountController.stream;

  @override
  dispose() {
    userAccountController.close();
  }

}