ExzileGames.AndroidFcmBridge 1.0.24

AndroidFcmBridge

A Java bridge + C# interop library for Firebase Cloud Messaging (FCM) on .NET Android. Provides async token retrieval, topic subscription, and push message callbacks for re-engagement notifications.

Problem

FirebaseMessagingService must be subclassed in Java and registered in the Android manifest — it cannot be implemented in C# alone. This library handles the Java side for you, forwarding token refreshes and incoming messages to your C# code via auto-generated JNI bindings.

APIs Exposed

Setup

1. Add google-services.json

Place your project's google-services.json file in the root of the consuming Android project. This file is obtained from the Firebase console and is required for FCM to initialise.

2. Register the service in AndroidManifest.xml

The ExzileFcmService must be declared in the consuming project's AndroidManifest.xml so that the Android system can route FCM events to the bridge:

<service android:name="com.exzilegames.fcmbridge.ExzileFcmService"
         android:exported="false">
    <intent-filter>
        <action android:name="com.google.firebase.MESSAGING_EVENT" />
    </intent-filter>
</service>

3. Add project reference

<ProjectReference Include="..\AndroidFcmBridge\AndroidFcmBridge.csproj" />

4. Initialize in your Activity

using AndroidFcmBridge.Interop;

protected override void OnCreate(Bundle? savedInstanceState)
{
    base.OnCreate(savedInstanceState);

    var fcm = new AndroidFcmBridgeImpl(this);
    FcmBridgeManager.SetImplementation(fcm);
}

5. Use from shared code

using AndroidFcmBridge.Interop;

// Listen for token refreshes (call before GetTokenAsync to avoid missing the first refresh)
FcmBridgeManager.SetTokenRefreshListener(token =>
{
    Console.WriteLine($"New FCM token: {token}");
    // Send token to your server
});

// Listen for incoming push messages
FcmBridgeManager.SetMessageListener(message =>
{
    Console.WriteLine($"Push received: {message.Title} — {message.Body}");
    foreach (var (key, value) in message.Data)
        Console.WriteLine($"  {key} = {value}");
});

// Retrieve the current token
var result = await FcmBridgeManager.GetTokenAsync();
if (result.Success)
    Console.WriteLine($"FCM token: {result.Token}");

// Subscribe to a topic
var sub = await FcmBridgeManager.SubscribeToTopicAsync("news");
if (!sub.Success)
    Console.WriteLine($"Subscribe failed: {sub.Message}");

// Unsubscribe from a topic
await FcmBridgeManager.UnsubscribeFromTopicAsync("news");

License

MIT