Flutter Firebase前台推送通知未显示但后台正在运行

Posted 2023-02-23

【中文标题】Flutter Firebase前台推送通知未显示但后台正在运行

【英文标题】：Flutter Firebase foreground push notification not showing but background is working

【发布时间】：2022-01-03 11:22:30

【问题描述】：

我已经好几天没有尝试解决这个问题了。我已经为推送通知实现了 Firebase 消息传递，因此，我能够在应用处于后台时接收通知，但 在应用处于前台时无法接收强>。我尝试了所有可能的解决方案或在 ***/github 上，但到目前为止没有任何效果。以下是我尝试过的来源：

*** solution 1

*** solution 2

当前代码 =>

NotificationService.dart:

class NotificationService 
  static final FlutterLocalNotificationsPlugin
      _flutterLocalNotificationsPlugin = FlutterLocalNotificationsPlugin();

  static Future initialize() async 
    final FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
        FlutterLocalNotificationsPlugin();

    androidInitializationSettings androidInitializationSettings =
        AndroidInitializationSettings('@mipmap/ic_launcher');

    InitializationSettings initializationSettings =
        InitializationSettings(android: androidInitializationSettings);

    await flutterLocalNotificationsPlugin.initialize(
      initializationSettings,
      // onSelectNotification: doSomething(),
    );
  

  static Future showNotification(RemoteMessage message) async 
    AndroidNotificationDetails androidDetails = AndroidNotificationDetails(
      "default_notification_channel_id",
      "channel",
      enableLights: true,
      enableVibration: true,
      priority: Priority.high,
      importance: Importance.max,
      largeIcon: DrawableResourceAndroidBitmap("ic_launcher"),
      styleInformation: MediaStyleInformation(
        htmlFormatContent: true,
        htmlFormatTitle: true,
      ),
      playSound: true,
    );

    await _flutterLocalNotificationsPlugin.show(
        message.data.hashCode,
        message.data['title'],
        message.data['body'],
        NotificationDetails(
          android: androidDetails,
        ));
  

main.dart:

Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async 
  await Firebase.initializeApp();
  print('Handling a background message $message.messageId');
  print('Notification Message: $message.data');
  NotificationService.showNotification(message);


void main() async 
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  FirebaseMessaging.onBackgroundMessage(_firebaseMessagingBackgroundHandler);
  runApp(
    MyApp(),
  );


class MyApp extends StatefulWidget 
  const MyApp(Key? key) : super(key: key);

  @override
  State<MyApp> createState() => _MyAppState();


class _MyAppState extends State<MyApp> 

  @override
  void initState() 
    super.initState();
    NotificationService.initialize();
    FirebaseMessaging.onMessage.listen((RemoteMessage message) 
      NotificationService.showNotification(message);
    );
  

  @override
  Widget build(BuildContext context) 
    return MaterialApp(...)

还有一点要补充的是，当应用程序处于后台（我可以收到通知的情况）时，我得到前两个print 语句的输出，即message.messageId 和@ 987654329@:

I/flutter ( 3363): Handling a background message 0:1637822186109880%5dd28a92f9fd7ecd
I/flutter ( 3363): Notification Message: body: Price is at Bull! Buy Now!, title: Hello Traders!

但是当应用程序处于前台（我没有收到通知的情况）时，我得到以下输出：D/FLTFireMsgReceiver( 3363): broadcast received for message

如果有人可以帮助我，那真的很有帮助，已经调试了几天，找到了解决方案。 谢谢！

AndroidManifest.xml:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.trading_app">

  <uses-permission android:name="android.permission.VIBRATE"/>
  <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
  <uses-permission android:name="android.permission.INTERNET"/>

   <application
        android:label="TradingApp"
        android:icon="@mipmap/ic_launcher">

        <meta-data
            android:name="com.google.firebase.messaging.default_notification_icon"
            android:resource="@mipmap/ic_launcher" />

        <meta-data         
            android:name="com.google.firebase.messaging.default_notification_channel_id"                 
            android:value="@string/default_notification_channel_id" />

        <receiver android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationBootReceiver">
        <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED"></action>
        </intent-filter>
        </receiver>
        <receiver android:name="com.dexterous.flutterlocalnotifications.ScheduledNotificationReceiver" />

        <activity
            android:name=".MainActivity"
            android:launchMode="singleTop"
            android:theme="@style/LaunchTheme"
            android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
            android:hardwareAccelerated="true"
            android:windowSoftInputMode="adjustResize">

            <meta-data
              android:name="io.flutter.embedding.android.NormalTheme"
              android:resource="@style/NormalTheme"
              />

            <meta-data
              android:name="io.flutter.embedding.android.SplashScreenDrawable"
              android:resource="@drawable/launch_background"
              />
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>

        <meta-data
            android:name="flutterEmbedding"
            android:value="2" />
            <!-- <meta-data
            android:name="com.google.firebase.messaging.default_notification_channel_id"
            android:value="high_importance_channel" /> -->
    </application>
</manifest>

【参考方案1】：

我不知道它是否适合你，但这是我的代码，用于在应用程序在前台时显示通知。我将 messageHandler 放在 initState() 上。 LocalNotification 是一个自定义类，因此您可以创建一个相同的类，或者将任何内容放在 showNotification 到 onMessage 中

  Future<void> messageHandler() async 
  await FirebaseMessaging.instance.setForegroundNotificationPresentationOptions(
    alert: true,
    badge: true,
    sound: true,
  );

  FirebaseMessaging.onMessage.listen((RemoteMessage event) 
    LocalNotification.showNotification(event);
  );



  static Future<void> showNotification(RemoteMessage payload) async 

    var android = AndroidInitializationSettings('logo_rs');
    var initiallizationSettingsios = IOSInitializationSettings();
    var initialSetting = new InitializationSettings(android: android, iOS: initiallizationSettingsIOS);
    final FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin = FlutterLocalNotificationsPlugin();
    flutterLocalNotificationsPlugin.initialize(initialSetting);



    const AndroidNotificationDetails androidDetails = AndroidNotificationDetails(
        'default_notification_channel_id',
        'Notification',
        'All Notification is Here',
        importance: Importance.max,
        priority: Priority.high,
        ticker: 'ticker',
        icon: "logo_rs",
        playSound: true,
        sound: RawResourceAndroidNotificationSound("notification")
    );
    const iOSDetails = IOSNotificationDetails();
    const NotificationDetails platformChannelSpecifics = NotificationDetails(android: androidDetails, iOS: iOSDetails);

    await flutterLocalNotificationsPlugin.show(0, payload.notification!.title, payload.notification!.body, platformChannelSpecifics);
  

添加尝试将其放在您的 AndroidManifest 中

   <meta-data  android:name="com.google.firebase.messaging.default_notification_channel_id"
                android:value="@string/default_notification_channel_id" />

String.xml（res/values 中的新文件）

<?xml version='1.0' encoding='utf-8'?>
<resources>
    <string name="default_notification_channel_id" translatable="false">fcm_default_channel</string>
</resources>

【讨论】：

您好，感谢您的回答，但我认为根据您的回答，我没有遗漏任何内容！仍然没有显示，也没有错误...

尝试将其放入您的 AndroidManifest <meta-data android:name="com.google.firebase.messaging.default_notification_channel_id" android:value="@string/default_notification_channel_id" /> 并将您的频道 ID 更改为 'default_notification_channel_id'

我按照你说的做了，但在调试时出现以下错误（构建失败）：Element meta-data#com.google.firebase.messaging.default_notification_channel_id at AndroidManifest.xml:61:13-63:55 duplicated with element declared at AndroidManifest.xml:16:9-18:71。我认为这是因为重复的meta-data ?。我用AndroidManifest.xml编辑了这个问题。

好的，那是因为有一个重复的meta-data（最后一个），我评论了它并且它构建成功但仍然看不到前台通知，后台通知正常工作.. .

【参考方案2】：

根据docs，

要在应用程序处于前台时收听消息，请收听 onMessage 流。

因此，您应该在此处打印您的消息 ID 和数据。

在您的 MyApp initState 中，

FirebaseMessaging.onMessage.listen((RemoteMessage message) 
  // print foreground message here.
  print('Handling a foreground message $message.messageId');
  print('Notification Message: $message.data');

  if (message.notification != null) 
    print('Message also contained a notification: $message.notification');
  

  //.. rest of your code
  NotificationService.showNotification(message);
);

【讨论】：

仍然，同样的输出，检查一些打印语句如何解决问题？

您的问题是前台通知未显示。我上面的代码将确认您的设备已收到它。然后你知道错误来自showNotification()。当您说“相同的输出”时，您的代码是否打印“正在处理前台消息...”？

不，它不打印Handling a foreground message，它只打印D/FLTFireMsgReceiver( 2809): broadcast received for message。好的，我明白你的意思了，那么 showNotification 可能有什么问题，因为它正在与 background 合作......