正确使用 Firebase 消息和 Flutter 的 onTokenRefresh() 方法

Question

I'm building a Flutter application and want to send Firebase Cloud Messaging notifications specifically to different users with their respective Firebase Token. The problem is when the app is reinstall or after some period of time, the Firebase Token is regenerated.

How can I use the onTokenRefresh() method to notice the change of token continuously (even when the app is not opened) and send the new token to my backend server?

Thank you.

Answer 1

The code should look like this:

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();

  await Firebase.initializeApp();
  FirebaseMessaging.instance.onTokenRefresh.listen((String token) {
    print("New token: $token");

  // sync token to server
  });

  String token = await FirebaseMessaging.instance.getToken();
  // sync token to server
  print("Token: $token");
  //runApp(MyApp());
}