在 Flutter App 中从后台接收 FCM 时如何显示自定义通知？

如何解决在 Flutter App 中从后台接收 FCM 时如何显示自定义通知？

1我正在使用 Flutter 开发一个聊天和 voip 应用程序。 当用户有来电时，我尝试实现自定义通知时遇到问题。

当应用程序处于前台时，自定义通知将显示良好。 问题是：当应用终止或在后台时，自定义通知不会显示。

我尝试了一些其他方法：

• 在本机代码中收听 FCM（MyFirebaseMessagingService，在 onMessageReceived 我调用 showNotification() 但它也不会显示
• 按照这篇 Medium 文章中的步骤操作：https://medium0.com/@info_67212/firebase-push-notification-with-action-button-in-flutter-a841da348097。它也不起作用

请帮助我。非常感谢

在 main.dart 中

 Future<void> _connectToAndroid() async {
    try {
      await platform.invokeMethod('connect');
    } on PlatformException catch (e) {
      print("EXCEPTION $e");
    }
  }

  void firebaseCloudMessaging_Listeners() {
    if (Platform.isIOS) iOS_Permission();
    _firebaseMessaging.getToken().then((token) {
      tokenFirebase = token;
      print('token $token');
    });

    _firebaseMessaging.configure(
      onMessage: (Map<String,dynamic> message) async {
        print('on 1111msg  $message');
        _connectToAndroid();
        _showNotification(jsonDecode(message['data']['ntf_data'])['title'],jsonDecode(message['data']['ntf_data'])['message'],jsonDecode(message['data']['ntf_data'])['conversationId']);
      },onResume: (Map<String,dynamic> message) async {
        print('on resume $message');
      },onBackgroundMessage: myBackgroundMessageHandler,onLaunch: (Map<String,dynamic> message) async {
        print('on launch $message');
      },);
  }

在 MainActivity.kt 中

class MainActivity : FlutterActivity() {
    private val CHANNEL = "connect"

    override fun configureFlutterEngine(@NonNull FlutterEngine: FlutterEngine) {
        super.configureFlutterEngine(FlutterEngine)
        MethodChannel(FlutterEngine.dartExecutor.binaryMessenger,CHANNEL).setMethodCallHandler { call,result ->
            Log.e("MainActivity","CHANNEL")
                result.success(null)
                showNotification()
        }
    }

    private fun showNotification() {
        val customView = RemoteViews(packageName,R.layout.custom_notification)
        //       val notificationIntent = Intent(this,CustomDialog::class.java)
//        val pendingIntent = PendingIntent.getActivity(this,notificationIntent,PendingIntent.FLAG_UPDATE_CURRENT)
//        val hungupPendingIntent = PendingIn4tent.getbroadcast(this,hungupIntent,PendingIntent.FLAG_UPDATE_CURRENT)
//        val answerPendingIntent = PendingIntent.getActivity(this,answerIntent,PendingIntent.FLAG_UPDATE_CURRENT)
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            val importance = notificationmanager.IMPORTANCE_HIGH
            val channel = NotificationChannel("CHANNEL_ID","name",importance).apply {
                description = "descriptionText"
            }
            // Register the channel with the system
            val notificationmanager: notificationmanager =
                    getSystemService(Context.NOTIFICATION_SERVICE) as notificationmanager
            notificationmanager.createNotificationChannel(channel)

            val newMessageNotification = Notification.Builder(context,"CHANNEL_ID")
                    .setSmallIcon(R.drawable.app_icon)
                    .setContentText("IncomingCall")
                    .setTicker("Call_STATUS")
                    .setTimeoutAfter(5000)
                    .setCategory(NotificationCompat.CATEGORY_CALL)
                    .setCustomContentView(customView)
                    .build()
            with(notificationmanagerCompat.from(applicationContext)) {
                // notificationId is a unique int for each notification that you must define
                notify(11111111,newMessageNotification)
            }
        }
    }
}

日志

2021-01-08 15:24:10.141 32759-3385/com.meeyland.meeyteam W/FirebaseMessaging: Notification Channel set in AndroidManifest.xml has not been created by the app. Default value will be used.
2021-01-08 15:24:10.213 32759-2410/com.meeyland.meeyteam V/FA: Connecting to remote service
2021-01-08 15:24:10.239 32759-2410/com.meeyland.meeyteam D/FA: Connected to remote service
2021-01-08 15:24:10.241 32759-2410/com.meeyland.meeyteam V/FA: Processing queued up service tasks: 1
2021-01-08 15:24:15.312 32759-2410/com.meeyland.meeyteam V/FA: Inactivity,disconnecting from the service
2021-01-08 15:24:15.319 32759-2410/com.meeyland.meeyteam W/ConnectionTracker: Exception thrown while unbinding
    java.lang.IllegalArgumentException: Service not registered: lu@7ace62f
        at android.app.LoadedApk.forgetServicedispatcher(LoadedApk.java:1751)
        at android.app.ContextImpl.unbindService(ContextImpl.java:1777)
        at android.content.Contextwrapper.unbindService(Contextwrapper.java:741)
        at ci.f(:com.google.android.gms.dynamite_measurementdynamite@204516083@20.45.16 (120408-0):1)
        at ci.d(:com.google.android.gms.dynamite_measurementdynamite@204516083@20.45.16 (120408-0):2)
        at lv.E(:com.google.android.gms.dynamite_measurementdynamite@204516083@20.45.16 (120408-0):9)
        at lf.a(:com.google.android.gms.dynamite_measurementdynamite@204516083@20.45.16 (120408-0):3)
        at ef.run(:com.google.android.gms.dynamite_measurementdynamite@204516083@20.45.16 (120408-0):3)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:462)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at iy.run(:com.google.android.gms.dynamite_measurementdynamite@204516083@20.45.16 (120408-0):5)