我想您知道如何将 firebase 添加到您的应用程序中.如果没有:https://firebase.google.com/docs/flutter/setup?platform=android

I suppose that you know how to add firebase to your App. If not: https://firebase.google.com/docs/flutter/setup?platform=android

将firebase添加到应用程序后，这就是我所做的:

After adding firebase to the App, this is what I do :

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();

  runApp(
    MaterialApp(
      debugShowCheckedModeBanner: false,
      routes: {
      '/': (context) =>  AppStarter(),
      '/message': (context) => NotificationDetails(),
      },
     ),
    );
   }



class AppStarter extends StatefulWidget{
   @override
   _AppStarterState createState() => _AppStarterState();
  }



class _AppStarterState extends State<AppStarter>
   {

     FirebaseMessaging messaging = FirebaseMessaging.instance;

    Future<void> showMeMyToken()
    async {
      var myToken = await messaging.getToken();
      print("My Token is: " + myToken.toString());
    }


    @override
    void initState() {
       super.initState();

       showMeMyToken();

      FirebaseMessaging.instance.getInitialMessage().then((value) {
       if(value != null)
        {
          Navigator.push(context,
          MaterialPageRoute(
              builder: (context){return NotificationDetails();},
          settings: RouteSettings(arguments: value.data,),
         ),
        );
       }
     });


     FirebaseMessaging.onMessage.listen((RemoteMessage message) {


        if (message.notification != null) {
           print('Message on Foreground: ${message.notification}');
              }
         });


      FirebaseMessaging.onMessageOpenedApp.listen((RemoteMessage message)
       {
         Navigator.push(
           context,
           MaterialPageRoute(
               builder: (context) {return NotificationDetails();},
               settings: RouteSettings(arguments: message.data,)
          ),
        );
     });

     FirebaseMessaging.onBackgroundMessage(firebaseMessagingBackgroundHandler);
   }


   @override
    Widget build(BuildContext context) {

      return MaterialApp(
        debugShowCheckedModeBanner: false,
        title: 'Just a Test',
        
        home: AppHome(),
       );
      }
   }




   Future<void> firebaseMessagingBackgroundHandler(RemoteMessage message) async {
     await Firebase.initializeApp();

      print("Handling a background message :-): ${message.data}");
      //Here you can do what you want with the message :-)
     }