当应用程序在前台时不显示通知

Question

I have added this code in the onMessageReceived method of the FirebaseNotificationService class which extends FirebaseMessagingService

Notification notification = new NotificationCompat.Builder(this)
            .setContentTitle(remoteMessage.getNotification().getTitle())
            .setContentText(remoteMessage.getNotification().getBody())
            .setSmallIcon(R.mipmap.ic_launcher)
            .build();
    NotificationManagerCompat manager = NotificationManagerCompat.from(getApplicationContext());
    manager.notify(123, notification);

But still, the notification isn't working when the app is in the foreground but works only when the app is in the background.

With this permission in AndroidManifest.xml :

<service android:name="com.codb.shoppingapp.utils.FirebaseNotificationService">
        <intent-filter>
            <action android:name="com.google.firebase.MESSANGING_EVENT" />
        </intent-filter>
    </service>

Answer 1

Try setting a notification channel id on the notification. Notification channels became required with Android O. If you leave it out, the notification will not show.

https://developer.android.com/training/notify-user/channels

Answer 2

FCM has two messages types: when your app is in the background.

• Notification message:

• Data message:

  1. Notification message: the notification is delivered to the device's system tray, not onMessageReceived

  2. Data message: always, the notification is delivered to onMessageReceived

so, You should send a format is Data Message to handle notification in onMessageReceived when the app is background or foreground