Azure Notification Hub - Android app crashing when receive notification - azure

Question

I'm using Azure Notification Hub with Firebase Cloud Messaging and Xamarin. When I have the app in the background or in use, I can receive notifications. But when I kill the app from the Android current app list, I'm able to receive one notification but after that, I have the error "my_app stopped (close the application)". Any idea why ? I don't have error log because it happens when the app is killed.
This is my code, from the documentation
using System;
using System.Collections.Generic;
using System.Text;
using Android.App;
using Android.Content;
using Android.Util;
using WindowsAzure.Messaging;
using Gcm.Client;
[assembly: Permission(Name = "#PACKAGE_NAME#.permission.C2D_MESSAGE")]
[assembly: UsesPermission(Name = "#PACKAGE_NAME#.permission.C2D_MESSAGE")]
[assembly: UsesPermission(Name ="com.google.android.c2dm.permission.RECEIVE")]
//GET_ACCOUNTS is needed only for Android versions 4.0.3 and below
[assembly: UsesPermission(Name = "android.permission.GET_ACCOUNTS")]
[assembly: UsesPermission(Name = "android.permission.INTERNET")]
[assembly: UsesPermission(Name = "android.permission.WAKE_LOCK")]
namespace Waka.Droid
{
[BroadcastReceiver(Permission = Gcm.Client.Constants.PERMISSION_GCM_INTENTS)]
[IntentFilter(new string[] { Gcm.Client.Constants.INTENT_FROM_GCM_MESSAGE },
Categories = new string[] { "#PACKAGE_NAME#" })]
[IntentFilter(new string[] { Gcm.Client.Constants.INTENT_FROM_GCM_REGISTRATION_CALLBACK },
Categories = new string[] { "#PACKAGE_NAME#" })]
[IntentFilter(new string[] { Gcm.Client.Constants.INTENT_FROM_GCM_LIBRARY_RETRY },
Categories = new string[] { "#PACKAGE_NAME#" })]
public class MyBroadcastReceiver : GcmBroadcastReceiverBase<PushHandlerService>
{
public static string[] SENDER_IDS = new string[] { Constants.SenderID };
public const string TAG = "MyBroadcastReceiver-GCM";
}
[Service] // Must use the service tag
public class PushHandlerService : GcmServiceBase
{
public static string RegistrationID { get; private set; }
private NotificationHub Hub { get; set; }
public PushHandlerService() : base(Constants.SenderID)
{
}
protected override void OnRegistered(Context context, string registrationId)
{
RegistrationID = registrationId;
Hub = new NotificationHub(Constants.NotificationHubName, Constants.ListenConnectionString,
context);
try
{
Hub.UnregisterAll(registrationId);
}
catch (Exception ex)
{
Log.Error(MyBroadcastReceiver.TAG, ex.Message);
}
//var tags = new List<string>() { "falcons" }; // create tags if you want
var tags = new List<string>() { };
try
{
var hubRegistration = Hub.Register(registrationId, tags.ToArray());
}
catch (Exception ex)
{
Log.Error(MyBroadcastReceiver.TAG, ex.Message);
}
}
protected override void OnMessage(Context context, Intent intent)
{
var msg = new StringBuilder();
if (intent != null && intent.Extras != null)
{
foreach (var key in intent.Extras.KeySet())
msg.AppendLine(key + "=" + intent.Extras.Get(key).ToString());
}
string messageText = intent.Extras.GetString("message");
if (!string.IsNullOrEmpty(messageText))
{
createNotification("Shotgun!", messageText);
}
else
{
createNotification("Undefined", msg.ToString());
}
}
void createNotification(string title, string desc)
{
//Create notification
var notificationManager = GetSystemService(Context.NotificationService) as NotificationManager;
//Create an intent to show UI
var uiIntent = new Intent(this, typeof(MainActivity));
PendingIntent resultPendingIntent =
PendingIntent.GetActivity(
this,
0,
uiIntent,
0
);
Notification noti = new Notification.Builder(this)
.SetContentTitle("" + title)
.SetContentText(desc)
.SetSmallIcon(Android.Resource.Drawable.SymActionEmail)
.SetContentIntent(resultPendingIntent)
.SetDefaults(NotificationDefaults.All)
.Build();
//Show the notification
notificationManager.Notify(1, noti);
dialogNotify(title, desc);
}
protected void dialogNotify(String title, String message)
{
MainActivity.instance.RunOnUiThread(() =>
{
AlertDialog.Builder dlg = new AlertDialog.Builder(MainActivity.instance);
AlertDialog alert = dlg.Create();
alert.SetTitle(title);
alert.SetButton("Ok", delegate
{
alert.Dismiss();
});
alert.SetMessage(message);
alert.Show();
});
}
protected override void OnUnRegistered(Context context, string registrationId)
{
}
protected override bool OnRecoverableError(Context context, string errorId)
{
return base.OnRecoverableError(context, errorId);
}
protected override void OnError(Context context, string errorId)
{
}
}
}
MainActivity.cs:
using System;
using Android.App;
using Android.Content;
using Android.Content.PM;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using Android.Util;
using Gcm.Client;
namespace Waka.Droid
{
[Activity(Label = "Waka.Droid", Icon = "#drawable/icon", Theme = "#style/MyTheme", MainLauncher = false, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
public static MainActivity instance;
protected override void OnCreate(Bundle bundle)
{
TabLayoutResource = Resource.Layout.Tabbar;
ToolbarResource = Resource.Layout.Toolbar;
base.OnCreate(bundle);
instance = this;
global::Xamarin.Forms.Forms.Init(this, bundle);
LoadApplication(new App());
RegisterWithGCM();
}
private void RegisterWithGCM()
{
// Check to ensure everything's set up right
GcmClient.CheckDevice(this);
GcmClient.CheckManifest(this);
// Register for push notifications
GcmClient.Register(this, Constants.SenderID);
}
}
}