Unable to receive FCM push notification when iOS application is in background - ios

Question

Currently I have been working on a xamarin ios application, and I am trying to implement push notification using firebase cloud messaging, I have updated the info.plist, Entitlement.plist
and also added the GoogleService-Info.plist i.e.
and here is what I have done in my AppDelegate.cs
using Foundation;
using UIKit;
using UserNotifications;
using Firebase.Core;
using Firebase.CloudMessaging;
using System;
using TrendSurveyApp.iOS;
using Newtonsoft.Json;
using System.Collections.Generic;
using AudioToolbox;
namespace CloudMessagingSample
{
// The UIApplicationDelegate for the application. This class is responsible for launching the
// User Interface of the application, as well as listening (and optionally responding) to application events from iOS.
[Register("AppDelegate")]
public class AppDelegate : UIApplicationDelegate, IUNUserNotificationCenterDelegate, IMessagingDelegate
{
public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)
{
// Override point for customization after application launch.
// If not required for your application you can safely delete this method
//(Window.RootViewController as UINavigationController).PushViewController(new DialogViewController1(this), true);
App.Configure();
Messaging.SharedInstance.Delegate = this;
UIRemoteNotificationType notificationTypes = UIRemoteNotificationType.Alert | UIRemoteNotificationType.Badge | UIRemoteNotificationType.Sound;
if (UIDevice.CurrentDevice.CheckSystemVersion(10, 0))
{
UNUserNotificationCenter.Current.Delegate = this;
UNUserNotificationCenter.Current.RequestAuthorization(UNAuthorizationOptions.Alert | UNAuthorizationOptions.Badge | UNAuthorizationOptions.Sound,
(granted, error) =>
{
if (granted)
{
InvokeOnMainThread(UIApplication.SharedApplication.RegisterForRemoteNotifications);
}
});
}
else if (UIDevice.CurrentDevice.CheckSystemVersion(8, 0))
{
var pushSettings = UIUserNotificationSettings.GetSettingsForTypes(
UIUserNotificationType.Alert | UIUserNotificationType.Badge | UIUserNotificationType.Sound,
new NSSet());
UIApplication.SharedApplication.RegisterUserNotificationSettings(pushSettings);
UIApplication.SharedApplication.RegisterForRemoteNotifications();
}
else
{
UIApplication.SharedApplication.RegisterForRemoteNotificationTypes(notificationTypes);
}
// To connect with FCM. FCM manages the connection, closing it
// when your app goes into the background and reopening it
// whenever the app is foregrounded.
Messaging.SharedInstance.ShouldEstablishDirectChannel = true;
return true;
}
public void DidReceiveRegistrationToken(Messaging messaging, string fcmToken)
{
// Monitor token generation: To be notified whenever the token is updated.
LogInformation(nameof(DidReceiveRegistrationToken), $"Firebase registration token: {fcmToken}");
// TODO: If necessary send token to application server.
// Note: This callback is fired at each app startup and whenever a new token is generated.
}
// You'll need this method if you set "FirebaseAppDelegateProxyEnabled": NO in GoogleService-Info.plist
public override void RegisteredForRemoteNotifications(UIApplication application, NSData deviceToken)
{
Messaging.SharedInstance.ApnsToken = deviceToken;
}
public override void DidReceiveRemoteNotification(UIApplication application, NSDictionary userInfo, Action<UIBackgroundFetchResult> completionHandler)
{
Messaging.SharedInstance.AppDidReceiveMessage(userInfo);
LogInformation(nameof(DidReceiveRemoteNotification), userInfo);
completionHandler(UIBackgroundFetchResult.NewData);
var myData = JsonConvert.DeserializeObject<List<string>>(userInfo[new NSString("webContentList")] as NSString);
}
[Export("messaging:didReceiveMessage:")]
public void DidReceiveMessage(Messaging messaging, RemoteMessage remoteMessage)
{
// Handle Data messages for iOS 10 and above.
HandleMessage(remoteMessage.AppData);
var fcmToken = Messaging.SharedInstance.FcmToken;
LogInformation(nameof(DidReceiveMessage), remoteMessage.AppData);
}
[Export("userNotificationCenter:willPresentNotification:withCompletionHandler:")]
public void WillPresentNotification(UNUserNotificationCenter center, UNNotification notification, Action<UNNotificationPresentationOptions> completionHandler)
{
SystemSound.Vibrate.PlayAlertSound();
SystemSound.Vibrate.PlaySystemSound();
completionHandler(UNNotificationPresentationOptions.Alert);
}
void HandleMessage(NSDictionary message)
{
if (message == null)
return;
MessageType messageType;
if (message.ContainsKey(new NSString("aps")))
messageType = MessageType.Notification;
else
messageType = MessageType.Data;
var e = new UserInfoEventArgs(message, messageType);
}
void LogInformation(string methodName, object information) => Console.WriteLine($"\nMethod name: {methodName}\nInformation: {information}");
}
}
Now the problem is when the app is in background i am not receiving any notification neither any callback function such as didReceivedNotification is being hit while if i have the app opened in the foreground i can receive notification !! Need Help

Answer 1

Try this:
public override bool FinishedLaunching(UIApplication application, NSDictionary launchOptions)
{
LoadApplication(new App());
Firebase.Core.App.Configure();
if (UIDevice.CurrentDevice.CheckSystemVersion(10, 0))
{
// iOS => 10
var authOptions = UNAuthorizationOptions.Alert | UNAuthorizationOptions.Badge | UNAuthorizationOptions.Sound;
UNUserNotificationCenter.Current.RequestAuthorization(authOptions, (granted, error) =>
{
//request authorization method
Console.WriteLine(granted);
});
// For iOS 10+ display notification (sent via APNS)
UNUserNotificationCenter.Current.Delegate = this;
}
else
{
// iOS 9 <=
var allNotificationTypes = UIUserNotificationType.Alert | UIUserNotificationType.Badge | UIUserNotificationType.Sound;
var settings = UIUserNotificationSettings.GetSettingsForTypes(allNotificationTypes, null);
UIApplication.SharedApplication.RegisterUserNotificationSettings(settings);
}
UIApplication.SharedApplication.RegisterForRemoteNotifications();
return base.FinishedLaunching(application, launchOptions);
}