Xamarin Forms using Azure Hubs. push notifications not showing on android when app is in running/active

Question

I followed the tutorial to add push notifications to a Xamarin Forms app. It works in iOS in all states: app not running or running in the background or active. For android I get the notifications when the app is not running or it's in the background but not when the app is active.

I am using:

Xamarin.Azure.NotificationHubs.Android 1.1.4.1. (1/28/2021)  
Xamarin.Firebase.Messaging 122.0.0 (6/11/2021)  

Heres in my code on Android:

    public class MainActivity : FormsAppCompatActivity  
    {  
        internal static readonly string CHANNEL_ID = "xxxxxx";  
        const string NotificationHubConnectionString = "xxxxxx";  
        const string NotificationHubName = "xxxxxx";  
  
        protected override void OnCreate(Bundle bundle)  
        {  
            .   
            .    
            .    
  
            NotificationHub.SetListener(new AzureListener());  
            NotificationHub.Start(this.Application, NotificationHubName, NotificationHubConnectionString);  
  
            .   
            .    
            .    
  
            LoadApplication(new App());  
        }  
  
    }  
  
  
public class AzureListener : Java.Lang.Object, INotificationListener  
{  
    public void OnPushNotificationReceived(Context context, INotificationMessage message)  
    {  
        var intent = new Intent(context, typeof(MainActivity));  
        intent.AddFlags(ActivityFlags.ClearTop);  
        var pendingIntent = PendingIntent.GetActivity(context, 0, intent, PendingIntentFlags.OneShot);  
  
        var notificationBuilder = new NotificationCompat.Builder(context, MainActivity.CHANNEL_ID);  
  
        notificationBuilder.SetContentTitle(message.Title)  
                    .SetSmallIcon(Resource.Drawable.icon_category_announcement)  
                    .SetContentText(message.Body)  
                    .SetAutoCancel(true)  
                    .SetShowWhen(false)  
                    .SetContentIntent(pendingIntent);  
  
        var notificationManager = NotificationManager.FromContext(context);  
  
        notificationManager.Notify(0, notificationBuilder.Build());  
    }  
}  

I followed the following tutorial from Microsoft (1/12/2021):

[https://learn.microsoft.com/en-us/azure/notification-hubs/xamarin-notification-hubs-push-notifications-android-gcm#set-up-notification-hubs-in-your-project][1]

In the tutorial there seems to be an issue on steps 11 and 12 because they talk about a class name from the previous tutorial but then they use the new class name and some instructions seem to be missing:

Step 11. Add the following above your class declaration, and have your class inherit from Java.Lang.Object and implement the INotificationListener:
=> There is nothing above the class declaration

Step 12. Add the following code inside MyFirebaseMessagingService class, to process messages that are received.
=> The class name is actually AzureListener

What am I missing? How can I make the push notification to show up when the app is running and active?

Answer 1

To benefit the community find answer/workaround easily, copying the workaround shared by Juan -from the SO thread

"
UPDATE: It looks like this code has nothing to do with that. The notification is shown by the OS. This code is to handle/show the notification when the app is active in the foreground. So in that case I am ok with showing just an alert. I was able to make this work simply doing this:

public class AzureListener : Java.Lang.Object, INotificationListener
{
    public void OnPushNotificationReceived(Context context, INotificationMessage message)
    {
        Device.BeginInvokeOnMainThread(() =>
        {
            Application.Current.MainPage.DisplayAlert(message.Title, message.Body, "OK");
        });
    }
}

"

Apologies for delay. Thanks again for the update, JuanGarzon-4997.