前景通知无法正常运行

Question

我是新来的。我正在从Firebase发送通知。它在后台运行，但在前台不运行。我也尝试了本地通知依赖项，但是它不起作用。

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  String textValue = 'Hello World !';
  FirebaseMessaging firebaseMessaging = new FirebaseMessaging();
  FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
  new FlutterLocalNotificationsPlugin();

  @override
  void initState() {
    super.initState();

    firebaseMessaging.getToken().then((token) {
      print('token');
      print('token $token');
    });

    var android = new AndroidInitializationSettings('mipmap/ic_launcher');
    var ios = new IOSInitializationSettings();
    var platform = new InitializationSettings(android, ios);
    flutterLocalNotificationsPlugin.initialize(platform);


    firebaseMessaging.configure(
      onLaunch: (Map<String, dynamic> msg) {
        print(" onLaunch called ${(msg)}");
      },
      onResume: (Map<String, dynamic> msg) {
        print(" onResume called ${(msg)}");
      },
      onMessage: (Map<String, dynamic> msg) {
        showNotification(msg);
        print(" onMessage called ${(msg)}");
      },
    );
    firebaseMessaging.requestNotificationPermissions(
        const IosNotificationSettings(sound: true, alert: true, badge: true));
    firebaseMessaging.onIosSettingsRegistered
        .listen((IosNotificationSettings setting) {
      print('IOS Setting Registed');
    });
  }

  void _incrementCounter() {
    setState(() {
      _counter++;
    });
  }

  showNotification(Map<String, dynamic> msg) async {
    var android = new AndroidNotificationDetails(
      'sdffds dsffds',
      "CHANNLE NAME",
      "channelDescription",
    );
    var iOS = new IOSNotificationDetails();
    var platform = new NotificationDetails(android, iOS);
    await flutterLocalNotificationsPlugin.show(
        0, "This is title", "this is demo", platform);
  }
    

Android清单文件

 <activity>
<meta-data
      android:name="com.google.firebase.messaging.default_notification_channel_id"
      android:value="default_notification_channel_id" />
<intent-filter>
      <action android:name="FLUTTER_NOTIFICATION_CLICK" />
      <category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>

它正在后台通知中工作。但它不能在前台工作。