Flutter中App关闭时无法接收FCM消息的问题求助

问题1：应用终止后FCM消息被取消（Logcat显示CANCELLED） #

核心原因 #

• Android 12对后台组件启动限制更严格，你的AndroidManifest.xml缺少FCM必需的服务与广播接收器配置
• 后台消息处理函数未初始化Firebase，导致无法在应用进程终止时处理消息

修复步骤 #

1. 补充AndroidManifest配置
   在<application>标签内添加以下FCM相关配置：

   <!-- 新增FCM所需权限 -->
   <uses-permission android:name="android.permission.WAKE_LOCK"/>
   <uses-permission android:name="com.google.android.c2dm.permission.RECEIVE"/>
   
   <!-- FCM消息处理服务 -->
   <service
       android:name="com.google.firebase.messaging.FirebaseMessagingService"
       android:exported="false">
       <intent-filter>
           <action android:name="com.google.firebase.MESSAGING_EVENT"/>
       </intent-filter>
   </service>
   
   <!-- C2DM广播接收器，处理高优先级消息 -->
   <receiver
       android:name="com.google.firebase.iid.FirebaseInstanceIdReceiver"
       android:exported="true"
       android:permission="com.google.android.c2dm.permission.SEND">
       <intent-filter>
           <action android:name="com.google.android.c2dm.intent.RECEIVE"/>
           <action android:name="com.google.android.c2dm.intent.REGISTRATION"/>
           <category android:name="${applicationId}"/>
       </intent-filter>
   </receiver>
   

2. 修正后台消息处理函数
   后台消息处理函数必须先初始化Firebase，才能正常处理并展示通知：

   Future<void> _onBackgroundMessageHandler(RemoteMessage message) async {
     // 必须初始化Firebase
     await Firebase.initializeApp();
     FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin = FlutterLocalNotificationsPlugin();
   
     // 初始化本地通知配置
     const AndroidInitializationSettings androidInitializationSettings = AndroidInitializationSettings('launch_background');
     const InitializationSettings initializationSettings = InitializationSettings(android: androidInitializationSettings);
     await flutterLocalNotificationsPlugin.initialize(initializationSettings);
   
     // 配置高优先级通知参数
     var androidDetails = const AndroidNotificationDetails(
       'com.test.app.notification_channel',
       'Test Notification Channel',
       channelDescription: 'Notification Channel for Test App for Android',
       priority: Priority.high,
       importance: Importance.max,
     );
     var generalNotificationDetails = NotificationDetails(android: androidDetails);
   
     // 展示后台通知
     if (message.notification != null) {
       await flutterLocalNotificationsPlugin.show(
         message.notification.hashCode,
         message.notification?.title,
         message.notification?.body,
         generalNotificationDetails,
         payload: jsonEncode(message.data),
       );
     }
     debugPrint('Background FCM NOTIFICATION[#${message.messageId}] - Data: ${message.data} Title: ${message.notification?.title} Body: ${message.notification?.body}');
   }
   

问题2：前台通知仅在托盘显示，不弹窗 #

核心原因 #

AndroidNotificationDetails未设置importance: Importance.max，Android 12要求明确指定高重要性才能触发弹窗提示。

修复步骤 #

修改_setupPushNotification中的androidDetails配置：

var androidDetails = const AndroidNotificationDetails(
  'com.test.app.notification_channel',
  'Test Notification Channel',
  channelDescription: 'Notification Channel for Test App for Android',
  priority: Priority.high,
  importance: Importance.max, // 新增此行，确保通知弹窗
  enableVibration: true, // 可选：增强通知提示
  enableLights: true,
);

同时检查Android系统的应用通知设置，确保对应通知渠道处于启用状态。

内容的提问来源于stack exchange，提问作者Ariel