Flutter Firebase 云消息推送通知

Question

有谁知道如何使用 Firebase Cloud Messaging 在 android 设备上接收推送通知？我正在使用 FirebaseMessaging ^8.0.0-dev.14 并且能够在 IOS 上接收通知。这是我的主要方法和通知方法：

Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
  // If you're going to use other Firebase services in the background, such as Firestore,
  // make sure you call `initializeApp` before using other Firebase services.
  await Firebase.initializeApp();

  print("Handling a background message: ${message.messageId}");
}

Future<void> channelCreate() async {
  const AndroidNotificationChannel channel = AndroidNotificationChannel(
    'high_importance_channel', // id
    'High Importance Notifications', // title
    'This channel is used for important notifications.', // description
    importance: Importance.max,
  );
  final FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
      FlutterLocalNotificationsPlugin();

  await flutterLocalNotificationsPlugin
      .resolvePlatformSpecificImplementation<
          AndroidFlutterLocalNotificationsPlugin>()
      ?.createNotificationChannel(channel);

  FirebaseMessaging.onMessage.listen((RemoteMessage message) {
    RemoteNotification notification = message.notification;
    AndroidNotification android = message.notification?.android;

    // If `onMessage` is triggered with a notification, construct our own
    // local notification to show to users using the created channel.
    if (notification != null && android != null) {
      flutterLocalNotificationsPlugin.show(
          notification.hashCode,
          notification.title,
          notification.body,
          NotificationDetails(
            android: AndroidNotificationDetails(
              channel.id,
              channel.name,
              channel.description,
              icon: android?.smallIcon,
              // other properties...
            ),
          ));
    }
  });
}

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  FirebaseMessaging.onBackgroundMessage(_firebaseMessagingBackgroundHandler);
  channelCreate();
  runApp(DFGAPP());
}

这是我请求通知权限的另一个文件：

class _MentorMainPageState extends State<MentorMainPage> {
  @override
  void initState() {
    super.initState();
    final fbm = FirebaseMessaging.instance;
    fbm.requestPermission();
  }
}