Firebase Messaging

[ir4ever]

Segui o passo a passo para implementar mas o onBackgroundMessage causa o erro:
E/flutter ( 5481): [ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: Invalid argument(s): Failed to setup background message handler! `onBackgroundMessage`
E/flutter ( 5481):           should be a TOP-LEVEL OR STATIC FUNCTION and should NOT be tied to a
E/flutter ( 5481):           class or an anonymous function.

Sem usar ele recebo a notificação em segundo plano. OnMessage também não funciona.

Flutter doctor sem erros.

Versões usadas:

 classpath 'com.android.tools.build:gradle:3.3.3'
 classpath 'com.google.gms:google-services:4.3.4'

Pubspec:

 firebase_messaging: ^7.0.3

Meu myBackgroudHandler:

Future<dynamic> myBackgroundMessageHandler(Map<String, dynamic> message) async {
    Notificacao _notificacao = Notificacao();
    setState(() {
      controllerGet.contadorNotificacao.value++;
    });
    final prefs = await SharedPreferences.getInstance();
    await prefs.setInt('contadorNotificacao', controllerGet.contadorNotificacao.value);
   
    if (message.containsKey('data')) {
      // Handle data message
      final dynamic data = message['data'];
      _notificacao.urlImagem = data['image'];
      _notificacao.titulo = data['title'];
      _notificacao.texto = data['body'];
   
    }

    _salvarNotificacao(_notificacao);

  }

@override
  void initState() {
    super.initState();
    _pageController = PageController();
    _iniciarFirebase();
    initFCM();
  }

 Future initFCM() async{

    _firebaseMessaging.configure(
      onMessage: (Map<String, dynamic> message) async {
        SizeWidgets size = SizeWidgets();
        size = _verificaTela();
        final data = message['data'];
        showDialog(
            context: context,
            builder: (context){
              return AlertDialog(
                title: Text(data['title'], textAlign: TextAlign.center, style: TextStyle(
                    fontSize: 24,
                    fontWeight: FontWeight.bold,
                    color: temaPadrao.primaryColor
                ),),
                content: Column(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    Padding(
                      padding: EdgeInsets.only(bottom: 16.0),
                      child: Container(
                        child: data['image'] != null ?
                        Image.network(data['image'], height: size.heigth * .2, width: size.width * .8, fit: BoxFit.fill,)
                            : Image.asset('assets/images/logo.png', height: size.heigth * .2, fit: BoxFit.fill,),
                      ),
                    ),
                    Text(data['body'], textAlign: TextAlign.center,),
                  ],
                ),
                actions: <Widget>[
                  FlatButton(
                    onPressed: (){
                      Navigator.pop(context);
                    },
                    child: Text('Ok'),
                  )
                ],
              );
            }
        );
        myBackgroundMessageHandler(message);
        print("onMessage: $message");
      },
      onLaunch: (Map<String, dynamic> message) async {
        myBackgroundMessageHandler(message);
        print("onLaunch: $message");

      },
      onResume: (Map<String, dynamic> message) async {
        myBackgroundMessageHandler(message);
        print("onResume: $message");

      },
      onBackgroundMessage: myBackgroundMessageHandler
    );
    _firebaseMessaging.requestNotificationPermissions(
        const IosNotificationSettings(sound: true, badge: true, alert: true));
    _firebaseMessaging.onIosSettingsRegistered
        .listen((IosNotificationSettings settings) {
      print("Settings registered: $settings");
    });
    _firebaseMessaging.getToken().then((String token) {
      assert(token != null);
      print("Push Messaging token: $token");
    });
  }

[TahaTesser]

Hi @Raphael-Jose-Ferraro-IRForever
You need to move myBackgroundMessageHandler out of any class and put it on the top or bottom. Do not put it inside any stateful or stateless .

Try this code sample

code sample

// Copyright 2019 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:async';

import 'package:firebase_core/firebase_core.dart';
import 'package:firebase_messaging/firebase_messaging.dart';
import 'package:flutter/material.dart';

Future<dynamic> myBackgroundMessageHandler(Map<String, dynamic> message) {
  if (message.containsKey('data')) {
    // Handle data message
    final dynamic data = message['data'];
  }

  if (message.containsKey('notification')) {
    // Handle notification message
    final dynamic notification = message['notification'];
  }

  // Or do other work.
}

final Map<String, Item> _items = <String, Item>{};
Item _itemForMessage(Map<String, dynamic> message) {
  final dynamic data = message['data'] ?? message;
  final String itemId = data['id'];
  final Item item = _items.putIfAbsent(itemId, () => Item(itemId: itemId))
    ..status = data['status'];
  return item;
}

class Item {
  Item({this.itemId});
  final String itemId;

  StreamController<Item> _controller = StreamController<Item>.broadcast();
  Stream<Item> get onChanged => _controller.stream;

  String _status;
  String get status => _status;
  set status(String value) {
    _status = value;
    _controller.add(this);
  }

  static final Map<String, Route<void>> routes = <String, Route<void>>{};
  Route<void> get route {
    final String routeName = '/detail/$itemId';
    return routes.putIfAbsent(
      routeName,
      () => MaterialPageRoute<void>(
        settings: RouteSettings(name: routeName),
        builder: (BuildContext context) => DetailPage(itemId),
      ),
    );
  }
}

class DetailPage extends StatefulWidget {
  DetailPage(this.itemId);
  final String itemId;
  @override
  _DetailPageState createState() => _DetailPageState();
}

class _DetailPageState extends State<DetailPage> {
  Item _item;
  StreamSubscription<Item> _subscription;

  @override
  void initState() {
    super.initState();
    _item = _items[widget.itemId];
    _subscription = _item.onChanged.listen((Item item) {
      if (!mounted) {
        _subscription.cancel();
      } else {
        setState(() {
          _item = item;
        });
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Item ${_item.itemId}"),
      ),
      body: Material(
        child: Center(child: Text("Item status: ${_item.status}")),
      ),
    );
  }
}

class PushMessagingExample extends StatefulWidget {
  @override
  _PushMessagingExampleState createState() => _PushMessagingExampleState();
}

class _PushMessagingExampleState extends State<PushMessagingExample> {
  String _homeScreenText = "Waiting for token...";
  bool _topicButtonsDisabled = false;

  final FirebaseMessaging _firebaseMessaging = FirebaseMessaging();
  final TextEditingController _topicController =
      TextEditingController(text: 'topic');

  Widget _buildDialog(BuildContext context, Item item) {
    return AlertDialog(
      content: Text("Item ${item.itemId} has been updated"),
      actions: <Widget>[
        FlatButton(
          child: const Text('CLOSE'),
          onPressed: () {
            Navigator.pop(context, false);
          },
        ),
        FlatButton(
          child: const Text('SHOW'),
          onPressed: () {
            Navigator.pop(context, true);
          },
        ),
      ],
    );
  }

  void _showItemDialog(Map<String, dynamic> message) {
    showDialog<bool>(
      context: context,
      builder: (_) => _buildDialog(context, _itemForMessage(message)),
    ).then((bool shouldNavigate) {
      if (shouldNavigate == true) {
        _navigateToItemDetail(message);
      }
    });
  }

  void _navigateToItemDetail(Map<String, dynamic> message) {
    final Item item = _itemForMessage(message);
    // Clear away dialogs
    Navigator.popUntil(context, (Route<dynamic> route) => route is PageRoute);
    if (!item.route.isCurrent) {
      Navigator.push(context, item.route);
    }
  }

  @override
  void initState() {
    super.initState();
    _firebaseMessaging.configure(
      onMessage: (Map<String, dynamic> message) async {
        print("onMessage: $message");
        _showItemDialog(message);
      },
      onBackgroundMessage: myBackgroundMessageHandler,
      onLaunch: (Map<String, dynamic> message) async {
        print("onLaunch: $message");
        _navigateToItemDetail(message);
      },
      onResume: (Map<String, dynamic> message) async {
        print("onResume: $message");
        _navigateToItemDetail(message);
      },
    );
    _firebaseMessaging.requestNotificationPermissions(
        const IosNotificationSettings(
            sound: true, badge: true, alert: true, provisional: true));
    _firebaseMessaging.onIosSettingsRegistered
        .listen((IosNotificationSettings settings) {
      print("Settings registered: $settings");
    });
    _firebaseMessaging.getToken().then((String token) {
      assert(token != null);
      setState(() {
        _homeScreenText = "Push Messaging token: $token";
      });
      print(_homeScreenText);
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: const Text('Push Messaging Demo'),
        ),
        // For testing -- simulate a message being received
        floatingActionButton: FloatingActionButton(
          onPressed: () => _showItemDialog(<String, dynamic>{
            "data": <String, String>{
              "id": "2",
              "status": "out of stock",
            },
          }),
          tooltip: 'Simulate Message',
          child: const Icon(Icons.message),
        ),
        body: Material(
          child: Column(
            children: <Widget>[
              Center(
                child: Text(_homeScreenText),
              ),
              Row(children: <Widget>[
                Expanded(
                  child: TextField(
                      controller: _topicController,
                      onChanged: (String v) {
                        setState(() {
                          _topicButtonsDisabled = v.isEmpty;
                        });
                      }),
                ),
                FlatButton(
                  child: const Text("subscribe"),
                  onPressed: _topicButtonsDisabled
                      ? null
                      : () {
                          _firebaseMessaging
                              .subscribeToTopic(_topicController.text);
                          _clearTopicText();
                        },
                ),
                FlatButton(
                  child: const Text("unsubscribe"),
                  onPressed: _topicButtonsDisabled
                      ? null
                      : () {
                          _firebaseMessaging
                              .unsubscribeFromTopic(_topicController.text);
                          _clearTopicText();
                        },
                ),
              ])
            ],
          ),
        ));
  }

  void _clearTopicText() {
    setState(() {
      _topicController.text = "";
      _topicButtonsDisabled = true;
    });
  }
}

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  FirebaseApp app = await Firebase.initializeApp();
  assert(app != null);
  runApp(
    MaterialApp(
      home: PushMessagingExample(),
    ),
  );
}

[ir4ever]

#1754

Resolved! Thanks for help!

[TahaTesser]

Hi @Raphael-Jose-Ferraro-IRForever
Given your last message I feel safe to close this issue, if you disagree please write in the comments and I will reopen it.
Thank you