当应用程序在前台时，通知消息似乎为空

Question

I have configured firebase-messaging and flutter_local_notifications to be able to show show push notifications both when app is in foreground and in background. However, when onMessage is triggered with the app on foreground, the message itself seems to be empty.

Configuration:

FirebaseMessaging fcm = FirebaseMessaging();

flutterLocalNotificationsPlugin =
FlutterLocalNotificationsPlugin();

var initializationSettingsAndroid =
AndroidInitializationSettings('drawable/ic_stat');

var initializationSettingsIOS = IOSInitializationSettings();

var initializationSettings = InitializationSettings(
    initializationSettingsAndroid, initializationSettingsIOS);

flutterLocalNotificationsPlugin.initialize(initializationSettings,
    selectNotification: (String payload) async {});


fcm.configure(
  onLaunch: (Map<String, dynamic> msg) {
    print("On launch $msg");
    showNotification(msg);
  },
  onResume: (Map<String, dynamic> msg) {
    print("On resume $msg");
    showNotification(msg);
  },
  onMessage: (Map<String, dynamic> msg) {
    print("On message $msg");
    showNotification(msg);
  },
);

Handler:

void showNotification(Map<String, dynamic> msg) async{
  print(msg);
  var notificationsChannel = new AndroidNotificationDetails(
      'my_package',
      'my_organization',
      'notification_channel',
      importance: Importance.Max,
      priority: Priority.High);

  var iOSPlatformChannelSpecifics = new IOSNotificationDetails();

  var platformChannelSpecifics = new NotificationDetails(
      notificationsChannel, iOSPlatformChannelSpecifics);

  await flutterLocalNotificationsPlugin.show(
      0, msg['title'], msg['body'], platformChannelSpecifics,);

  }

Log when app in foreground:

W/FirebaseMessaging(10901): Error while parsing timestamp in GCM event
W/FirebaseMessaging(10901): java.lang.NumberFormatException: null
W/FirebaseMessaging(10901):     at java.lang.Integer.parseInt(Integer.java:483)
W/FirebaseMessaging(10901):     at java.lang.Integer.parseInt(Integer.java:556)
W/FirebaseMessaging(10901):     at com.google.firebase.messaging.zzb.zzc(Unknown Source)
W/FirebaseMessaging(10901):     at com.google.firebase.messaging.zzb.zze(Unknown Source)
W/FirebaseMessaging(10901):     at com.google.firebase.messaging.FirebaseMessagingService.zzd(Unknown Source)
W/FirebaseMessaging(10901):     at com.google.firebase.iid.zzc.run(Unknown Source)
W/FirebaseMessaging(10901):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
W/FirebaseMessaging(10901):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
W/FirebaseMessaging(10901):     at com.google.android.gms.common.util.concurrent.zza.run(Unknown Source)
W/FirebaseMessaging(10901):     at java.lang.Thread.run(Thread.java:761)
W/FirebaseMessaging(10901): Error while parsing timestamp in GCM event
W/FirebaseMessaging(10901): java.lang.NumberFormatException: null
W/FirebaseMessaging(10901):     at java.lang.Integer.parseInt(Integer.java:483)
W/FirebaseMessaging(10901):     at java.lang.Integer.parseInt(Integer.java:556)
W/FirebaseMessaging(10901):     at com.google.firebase.messaging.zzb.zzc(Unknown Source)
W/FirebaseMessaging(10901):     at com.google.firebase.messaging.zzb.zzh(Unknown Source)
W/FirebaseMessaging(10901):     at com.google.firebase.messaging.FirebaseMessagingService.zzd(Unknown Source)
W/FirebaseMessaging(10901):     at com.google.firebase.iid.zzc.run(Unknown Source)
W/FirebaseMessaging(10901):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
W/FirebaseMessaging(10901):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
W/FirebaseMessaging(10901):     at com.google.android.gms.common.util.concurrent.zza.run(Unknown Source)
W/FirebaseMessaging(10901):     at java.lang.Thread.run(Thread.java:761)
I/flutter (10901): On message {}
I/flutter (10901): {}
E/flutter (10901): [ERROR:flutter/shell/common/shell.cc(181)] Dart Error: Unhandled exception:
E/flutter (10901): NoSuchMethodError: The method '[]' was called on null.
E/flutter (10901): Receiver: null
E/flutter (10901): Tried calling: []("title")

However, when the app is in background, the notification is delivered directly to the system tray and it isn't empty (screenshot) .

Here's my flutter doctor output:

    [✓] Flutter (Channel beta, v0.8.2, on Mac OS X 10.13.5 17F77, locale es-ES)
    • Flutter version 0.8.2 at /Users/alex/Documents/Development/flutter
    • Framework revision 5ab9e70727 (3 weeks ago), 2018-09-07 12:33:05 -0700
    • Engine revision 58a1894a1c
    • Dart version 2.1.0-dev.3.1.flutter-760a9690c2

[✓] Android toolchain - develop for Android devices (Android SDK 27.0.3)
    • Android SDK at /Users/alex/Library/Android/sdk
    • Android NDK location not configured (optional; useful for native profiling support)
    • Platform android-27, build-tools 27.0.3
    • ANDROID_HOME = /Users/alex/Library/Android/sdk
    • Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b01)
    • All Android licenses accepted.

[✓] iOS toolchain - develop for iOS devices (Xcode 9.4.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 9.4.1, Build version 9F2000
    • ios-deploy 1.9.2
    • CocoaPods version 1.5.3

[✓] Android Studio (version 3.1)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin version 26.0.1
    • Dart plugin version 173.4700
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b01)

[✓] IntelliJ IDEA Ultimate Edition (version 2018.1.1)
    • IntelliJ at /Applications/IntelliJ IDEA.app
    • Flutter plugin version 26.0.2
    • Dart plugin version 181.4445.29

[✓] VS Code (version 1.27.2)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 2.18.0

[✓] Connected devices (1 available)
    • Android SDK built for x86 • emulator-5554 • android-x86 • Android 7.0 (API 24) (emulator)

• No issues found!

Maybe this has something to do with how firebase messages work?

Answer 1

这是通过将 (1) firebase-messaging和 (2) flutter_local_notifications到最新版本来解决的。