FMC احدث اصدار من Flutter

السلام عليكم ورحمة الله وبركاته 

تحيه طيبه للجميع 

قمت بستعمال احدث اصدار من اشعارات فايربيز في فلاتر الكود شغال اذا كنت خارج التطبيق لا توجد مشكله ولكن لو كنت داخل التطبيق لا يتم عرض الاشعارات للمستخدم

لا اعلم ما هو الجزء المتبقي في الامر 

الكود كامل:

Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
  print("Handling a background message: ${message.messageId}");
}

void main() async {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return
      MaterialApp(
        title: 'Notify',
        theme: ThemeData(
          primarySwatch: Colors.deepPurple,
        ),
        debugShowCheckedModeBanner: false,
        home: HomePage(),

    );
  }
}

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
   FirebaseMessaging _messaging;
   int _totalNotifications;
  PushNotification _notificationInfo;

  void registerNotification() async {
    await Firebase.initializeApp();_messaging = FirebaseMessaging.instance;

    FirebaseMessaging.onBackgroundMessage(_firebaseMessagingBackgroundHandler);

    NotificationSettings settings = await _messaging.requestPermission(
      alert: true,
      badge: true,
      provisional: false,
      sound: true,
    );

    if (settings.authorizationStatus == AuthorizationStatus.authorized) {
      print('User granted permission');

      FirebaseMessaging.onMessage.listen((RemoteMessage message) {
        print(
            'Message title: ${message.notification?.title}, body: ${message.notification?.body}, data: ${message.data}');

        // Parse the message received
        PushNotification notification = PushNotification(
          title: message.notification?.title,
          body: message.notification?.body,
          dataTitle: message.data['title'],
          dataBody: message.data['body'],
        );

        setState(() {
          _notificationInfo = notification;
          _totalNotifications++;
        });

        if (_notificationInfo != null) {

          showNotification;

        }
      });
    } else {
      print('User declined or has not accepted permission');
    }
  }
   static void showNotification(String title, String body) async {
     await _demoNotification(title, body);
   }
   static Future<void> _demoNotification(String title, String body) async {
     var androidPlatformChannelSpecifics = AndroidNotificationDetails(
         'channel_ID', 'channel name', 'channel description',
         importance: Importance.max,
         playSound: true,
         // sound: 'sound',
         // sound: true,
         showProgress: true,
         priority: Priority.high,
         ticker: 'test ticker');

     var iOSChannelSpecifics = IOSNotificationDetails();
     var platformChannelSpecifics = NotificationDetails(
         android: androidPlatformChannelSpecifics, iOS: iOSChannelSpecifics);
     await flutterLocalNotificationsPlugin
         .show(0, title, body, platformChannelSpecifics, payload: 'test');
   }
   static FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
   new FlutterLocalNotificationsPlugin();

   static void initialization(){
     var initializationSettingsAndroid =
     new AndroidInitializationSettings('@mipmap/ic_launcher');
     var initializationSettingsIOS = new IOSInitializationSettings();
     var initializationSettings = new InitializationSettings(
         android: initializationSettingsAndroid, iOS: initializationSettingsIOS);

     flutterLocalNotificationsPlugin = new FlutterLocalNotificationsPlugin();
     flutterLocalNotificationsPlugin.initialize(initializationSettings,
         onSelectNotification: onSelectNotification);
   }

   static Future onSelectNotification(String payload) async {
     showDialog(
       //   context: context,
       builder: (_) {
         return new AlertDialog(
           title: Text("PayLoad"),
           content: Text("Payload : $payload"),
         );
       },
     );
   }
   // For handling notification when the app is in terminated state
  checkForInitialMessage() async {
    await Firebase.initializeApp();
    RemoteMessage initialMessage =
        await FirebaseMessaging.instance.getInitialMessage();

    if (initialMessage != null) {
      PushNotification notification = PushNotification(
        title: initialMessage.notification?.title,
        body: initialMessage.notification?.body,
        dataTitle: initialMessage.data['title'],
        dataBody: initialMessage.data['body'],
      );

      setState(() {
        _notificationInfo = notification;
        _totalNotifications++;
      });
    }
  }



  @override
  void initState() {
    _totalNotifications = 0;
    registerNotification();
    checkForInitialMessage();

    FirebaseMessaging.onMessageOpenedApp.listen((RemoteMessage message) {
      PushNotification notification = PushNotification(
        title: message.notification?.title,
        body: message.notification?.body,

        dataTitle: message.data['title'],
        dataBody: message.data['body'],
      );

      setState(() {
        _notificationInfo = notification;
        _totalNotifications++;
      });
    });

    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Notify'),
        brightness: Brightness.dark,
      ),
      body: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [

        ],
      ),
    );
  }
}