Local Notifications are not showing in API 27

Question

Notifications are working for Api 26 and below perfectly but they are not working with API 27.

Here is my code for create notification channel:

private void CreateNotificationChannel()
{
    try
    {
        if (Build.VERSION.SdkInt < BuildVersionCodes.O)
        {
            return;
        }

        var notificationManager = (NotificationManager)GetSystemService(NotificationService);
        NotificationChannel mChannel = notifManager.GetNotificationChannel("1");
        if (mChannel == null)
        {
            mChannel = new NotificationChannel("1", "Chat Application", Android.App.NotificationImportance.High);
            mChannel.EnableVibration(true);
            mChannel.SetVibrationPattern(new long[] { 100, 200, 300, 400, 500, 400, 300, 200, 400 });
            notifManager.CreateNotificationChannel(mChannel);
        }
    }
    catch (Exception exception)
    {
        LoggingManager.Error(exception);
    }

}

And my notification Service is:

var activity = Forms.Context as Activity;

Intent intent = new Intent(activity, typeof(MainActivity));
intent.AddFlags(ActivityFlags.ClearTop);
Random random = new Random();
int pushCount = random.Next(9999 - 1000) + 1000; //for multiplepushnotifications

intent.AddFlags(ActivityFlags.ClearTop);
var pendingIntent = PendingIntent.GetActivity(activity, pushCount, intent, PendingIntentFlags.Immutable);

// Instantiate the builder and set notification elements:
NotificationCompat.Builder builder = new NotificationCompat.Builder(Forms.Context,"1")
                                                           .SetContentTitle(messageTitle)
                                                           .SetDefaults(1|2)
                                                           .SetContentText(Message)
                                                           .SetContentIntent(pendingIntent)
                                                           .SetAutoCancel(true)
                                                           .SetChannelId("1")
                                                           .SetPriority(1);
builder.SetSmallIcon(Resource.Drawable.icon);

// Build the notification:
Notification notification = builder.Build();

// Get the notification manager:
NotificationManager notificationManager = Forms.Context.GetSystemService(Context.NotificationService) as NotificationManager;

// Publish the notification:
notificationManager.Notify(5, notification);

Please help me out or give me some suggestions how can I resolve this issue.

Answer 1

Can you please try with notificationManager.Notify(new Random().Next(), notification);

instead of notificationManager.Notify(5, notification);

Answer 2

I have a feeling there is something wrong with your channel creation, below you can check my working piece of code.

 var mChannel = new NotificationChannel(CHANNEL_ID, "Chat Application", Android.App.NotificationImportance.High)
                  {
                      Description = "Firebase Cloud Messages appear in this channel"
                  };
        mChannel.EnableVibration(true);
        mChannel.SetVibrationPattern(new long[] { 100, 200, 300, 400, 500, 400, 300, 200, 400 });           

    var notificationManager = (NotificationManager) GetSystemService(NotificationService);
    notificationManager.CreateNotificationChannel(channel);