Flutter iOS应用终止时如何实现FCM数据消息推送通知？

核心原因说明 #

iOS系统对纯FCM Data消息的处理有严格限制：当APP处于终止状态时，纯Data消息不会触发系统唤醒APP，也不会显示通知。只有同时包含notification和data字段的混合推送消息，才会由APNs在通知栏展示，用户点击后才会将data传递给APP。这是iOS系统的原生限制，第三方插件无法绕过。

方案一：Flutter纯FCM配置优化 #

1. 调整推送消息结构 #

发送推送时必须同时包含notification和data字段，示例Payload：

{
  "to": "/topics/your_topic",
  "notification": {
    "title": "通知标题",
    "body": "通知内容"
  },
  "data": {
    "key1": "value1",
    "key2": "value2"
  },
  "apns": {
    "payload": {
      "aps": {
        "content-available": 1
      }
    }
  }
}

• content-available: 1用于触发后台刷新，确保后台状态下能正常接收数据。

2. 完善FCM插件配置 #

使用官方firebase_messaging插件，确保以下配置正确：

• 在Info.plist中添加后台权限配置：

  <key>UIBackgroundModes</key>
  <array>
    <string>remote-notification</string>
  </array>
  <key>FirebaseAppDelegateProxyEnabled</key>
  <false/>
  

• 配置后台消息处理器与初始化逻辑：

  Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
    await Firebase.initializeApp();
    print('收到后台消息: ${message.data}');
    // 这里添加自定义消息处理逻辑
  }
  
  void main() async {
    WidgetsFlutterBinding.ensureInitialized();
    await Firebase.initializeApp();
    FirebaseMessaging.onBackgroundMessage(_firebaseMessagingBackgroundHandler);
    
    // 请求完整推送权限（必须包含alert）
    NotificationSettings settings = await FirebaseMessaging.instance.requestPermission(
      alert: true,
      badge: true,
      sound: true,
    );
    
    // 订阅目标主题
    await FirebaseMessaging.instance.subscribeToTopic('your_topic');
    
    runApp(MyApp());
  }
  

• 监听APP从终止状态被通知唤醒的情况：

  @override
  void initState() {
    super.initState();
    FirebaseMessaging.instance.getInitialMessage().then((RemoteMessage? message) {
      if (message != null) {
        print('终止状态启动收到数据: ${message.data}');
        // 跳转对应页面或执行业务逻辑
      }
    });
  }
  

方案二：Swift原生结合Method Channel实现 #

如果插件配置后仍存在问题，可通过原生代码直接处理推送，再将数据传递给Flutter：

1. 原生端配置（Swift） #

修改AppDelegate.swift

import UIKit
import Flutter
import FirebaseMessaging
import UserNotifications

@UIApplicationMain
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    FirebaseApp.configure()
    
    // 请求推送权限
    UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .badge, .sound]) { granted, error in
      if granted {
        DispatchQueue.main.async {
          application.registerForRemoteNotifications()
        }
      }
    }
    
    // 处理APP终止状态下由通知启动的情况
    if let remoteNotification = launchOptions?[.remoteNotification] as? [String: Any] {
      let channel = FlutterMethodChannel(name: "com.example.push_handler", binaryMessenger: window?.rootViewController as! FlutterBinaryMessenger)
      channel.invokeMethod("receivePushData", arguments: remoteNotification)
    }
    
    GeneratedPluginRegistrant.register(with: self)
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
  
  // 处理后台/前台收到的推送
  override func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
    let channel = FlutterMethodChannel(name: "com.example.push_handler", binaryMessenger: window?.rootViewController as! FlutterBinaryMessenger)
    channel.invokeMethod("receivePushData", arguments: userInfo)
    completionHandler(.newData)
  }
  
  // 绑定APNs Token到FCM并订阅主题
  override func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
    Messaging.messaging().apnsToken = deviceToken
    Messaging.messaging().subscribe(toTopic: "your_topic") { error in
      if let error = error {
        print("订阅主题失败: \(error.localizedDescription)")
      } else {
        print("订阅主题成功")
      }
    }
  }
}

2. Flutter端监听Method Channel #

class _MyAppState extends State<MyApp> {
  late MethodChannel _pushChannel;

  @override
  void initState() {
    super.initState();
    _pushChannel = MethodChannel('com.example.push_handler');
    _pushChannel.setMethodCallHandler((MethodCall call) async {
      if (call.method == 'receivePushData') {
        Map<String, dynamic> pushData = Map<String, dynamic>.from(call.arguments as Map);
        print('原生传递的推送数据: $pushData');
        // 这里添加Flutter端的消息处理逻辑
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(home: Scaffold(body: Center(child: Text('Push Demo'))));
  }
}

关键注意事项 #

• 必须使用真实iOS设备测试，模拟器无法接收APNs推送。
• 确保APNs证书和FCM的GoogleService-Info.plist已正确配置到Xcode项目中。
• 推送权限必须请求到alert权限，provisional权限在终止状态下不会触发通知展示。

内容的提问来源于stack exchange，提问作者Sanket Vanani