Firebase notifications - subscribing to topics using iOS FCM token failing all the time… using C# API

Question

I have an App - Android and iOS with a partial web view.

I'm using a C# API back end and notifications via Firebase Cloud messaging works fine for Android, especially subscribing and unsubscribing to topics using the "registered" FM token.

Every time I try to subscribe to a topic using a FCM token that comes from an iOS device it fails.

I'm using very simple code to add tokens to topics e.g.

using (var httpRequest = new HttpRequestMessage(HttpMethod.Post, "https://iid.googleapis.com/iid/v1/" + [fcmToken] + "/rel/topics/" + [topic name])) {

httpRequest.Headers.TryAddWithoutValidation("Authorization", [server key]);
httpRequest.Headers.TryAddWithoutValidation("Sender", [sender id]);
httpRequest.Content = new StringContent(jsonBody, Encoding.UTF8, "application/json");

using (var httpClient = new HttpClient())
{
    var result = await httpClient.SendAsync(httpRequest);
    if (result.IsSuccessStatusCode)
    {
        //success
    }
    else
    {
       //failed
    }
}

}

Has anyone had any experience like this or a solution that I'm missing as to why iOS tokens are not getting subscribed to topics?

Gleydar Gleydar · Accepted Answer · 2018-11-07T12:22:41

Seeing as your code works fine for Android, but not for iOS I would follow the differences you need to pay attention to:

Did you initialize Firebase correctly for iOS? You might need to manually map your APN token to the Firebase token (https://firebase.google.com/docs/cloud-messaging/ios/client)
Did you upload the APN certificate to Firebase? (https://firebase.google.com/docs/cloud-messaging/ios/certs)
Do you correctly use the Notification Center if you want to display notifications?

Firebase notifications - subscribing to topics using iOS FCM token failing all the time… using C# API

1 Answers