问如何使用in_app_update迫使用户从play商店更新应用程序

EN

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class _TnPState extends State<TnP> {
  ThemeBloc _themeBloc;
  FirebaseMessaging _firebaseMessaging;
  NotificationBloc _notificationBloc;
  String _test;

  @override
  void initState() {
    _themeBloc = ThemeBloc();
    _firebaseMessaging = FirebaseMessaging();
    _notificationBloc = NotificationBloc();
    _firebaseMessaging.configure(
      onMessage: (notification) async => _notificationBloc.yes(),
      onResume: (notification) async => _notificationBloc.yes(),
      onLaunch: (notification) async => _notificationBloc.yes(),
    );
    checkForUpdate();
    super.initState();
  }

  Future<void> checkForUpdate() async {
    InAppUpdate.checkForUpdate().then((info) {
      String display = info.toString();
      setState((){
        _test = display;
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    return StreamBuilder<AppTheme>(
      stream: _themeBloc.themeStream,
      initialData: AppTheme.Light,
      builder: (context, AsyncSnapshot<AppTheme> snapshot) {
        return MaterialApp(
          title: 'TnP',
          debugShowCheckedModeBanner: false,
          theme: appThemeData[snapshot.data],
          home: _test==null ?
                Container() : 
                InAppUpdateScreen(display: _test),//SplashScreen(),
        );
      },
    );
  }
}