Flutter Firebase Messaging trigger onLaunch

问题

So I have a question, because I am not fully understand something. So I wrote a simple app, to try something, so I send a message from Firebase via Firebase Cloud Messaging. I use the firebase_messaging flutter plugin (7.0.3 version). It just does a simple thing to get the message and navigate to another page. My problem is the following one, the onMessage and the onResume function works perfectly, but when the app is terminated and I click on the notification the app opens but nothing happens. So I read the documentation and I found this The third row says, that the data is lost... Does this mean that I lost every data in the payload? My code is here if it helps

 static final NavigationService _navigationService =
      loc.Locator.locator<NavigationService>();
  final FirebaseMessaging _firebaseMessaging = FirebaseMessaging();

  Future<void> reqPermission() async {
    bool permission = true;
    if (Platform.isIOS) {
      permission = await _firebaseMessaging.requestNotificationPermissions();
    }
    if (permission) {
      _firebaseMessaging.configure(
        onMessage: (Map<String, dynamic> message) async {
          print(message);
          await _navigationService.navigateTo(NewPage.routeName);
        },
        onLaunch: (Map<String, dynamic> message) async {
          print('onLaunch $message');
          await _navigationService.navigateTo(NewPage.routeName);
        },
        onResume: (Map<String, dynamic> message) async {
          print('onResume $message');
          await _navigationService.navigateTo(NewPage.routeName);
        },
        onBackgroundMessage: _myBackgroundHandler,
      );
    }
  }

回答1:

you can send notifiction and data with fcm it supports notifiction on terminated but not data. You can able send body and title in notification so if you want to need basic notification (which only has title and body). You can send it with using notification. If you need more than that, you can use it with flutter_local_notifications package in onLaunch. https://pub.dev/packages/flutter_local_notifications

This is how to use tokens

_firebaseMessaging.onTokenRefresh.listen((newToken) {
      User _currentUser = FirebaseAuth.instance.currentUser;
      FirebaseFirestore.instance
          .doc("tokens/" + _currentUser.uid)
          .set({"token": newToken});
    });

and you can push it like that.

  Future<bool> sendNotification(
      {@required Map<String, dynamic> messageMap,
      @required AppUser appUser,
      @required String token}) async {
    String url = "https://fcm.googleapis.com/fcm/send";
    String _firebaseKey ="<your key>"

    Map<String, String> headers = {
      "Content-type": "application/json",
      "Authorization": "key=$_firebaseKey"
    };
    String json =
        '{ "to" : "$token", "data" : { "message" : "${messageMap["message"]}", "sendBy": "${appUser.name}", "messageType": "${messageMap["messageType"]}", "sendById" : "${appUser.userId}" } }';
    http.post(url, headers: headers, body: json);
    return true;
  }

FCM configurtion

_firebaseMessaging.configure(
      onMessage: (Map<String, dynamic> message) async {
        print("onMessage: $message");
        //getNotificationMessage(message["data"]["message"]);
        if(message["data"]["messageType"]=="text"){
          NotificationHandler.showNotification(message); // Flutter Local Notification method
        } else{
          NotificationHandler.showBigPictureNotification(message);// Flutter Local Notification method
        }
      },
      onLaunch: (Map<String, dynamic> message) async {
        print("onLaunch: $message");
        if(message["data"]["messageType"]=="text"){
          NotificationHandler.showNotification(message);// Flutter Local Notification method
        } else{
          NotificationHandler.showBigPictureNotification(message);// Flutter Local Notification method
        }
      },
      onResume: (Map<String, dynamic> message) async {
        if(message["data"]["messageType"]=="text"){
          NotificationHandler.showNotification(message);// Flutter Local Notification method
        } else{
          NotificationHandler.showBigPictureNotification(message);// Flutter Local Notification method
        }
      },
      onBackgroundMessage: myBackgroundMessageHandler,
    );
  }

This is background message handler

Future<void> myBackgroundMessageHandler(Map<String, dynamic> message) async {
  if (message.containsKey('data')) {
    // Handle data message
    final dynamic data = message['data'];
    if(message["data"]["messageType"]=="text"){
      NotificationHandler.showNotification(message);// Flutter Local Notification method
    } else{
      NotificationHandler.showBigPictureNotification(message);// Flutter Local Notification method
    }

  }

  return Future.value();
}

This is how i did it in my project

来源：https://stackoverflow.com/questions/65703938/flutter-firebase-messaging-trigger-onlaunch