Flutter - FCM 远程/静音通知（后台应用）

Question

我有一个需要接收 FCM 推送消息（静默/后台数据消息）的 Flutter 应用。我没有使用 Flutter 的 Firebase Cloud Messaging 插件，因为它目前不支持后台模式。因此，我已根据 IOS 的 Firebase 文档将 FCM IOS sdk 集成到项目中。

我可以很好地接收“通知”消息（当推送消息到达时向用户显示通知）。所以我相信我的设置（keys/fcm）很好。

现在的问题是，当我发送数据消息（不希望应用向用户显示通知）时，什么也没有发生。

我的消息看起来像

{
  "to": "fcm-token",
  "content_available": true,
  "apns-priority": 5,
  "data": {
    "some_key": "some_value"
  }
} 

我希望上面的数据消息会触发下面的委托方法（但它不会）。

override func application(_ application: UIApplication,
                              didReceiveRemoteNotification userInfo: [AnyHashable : Any],
                              fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void)

我已尝试启用或禁用方法调配，但这也无济于事。

以下是我为 FCM 消息传递设置委托的方式

extension AppDelegate : MessagingDelegate {
    override func application(_ application: UIApplication,
                              didReceiveRemoteNotification userInfo: [AnyHashable : Any],
                              fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void){
        print("didReceiveRemoteNotification")
        completionHandler(.newData)
    }
    
    func initFirebase(_ application: UIApplication) {
        FirebaseApp.configure()
        Messaging.messaging().delegate = self
        
        if #available(iOS 10.0, *) {
            UNUserNotificationCenter.current().delegate = self
            
            let authOptions: UNAuthorizationOptions = [.alert, .badge, .sound]
            UNUserNotificationCenter.current().requestAuthorization(
                options: authOptions,
                completionHandler: {_, _ in })
        } else {
            let settings: UIUserNotificationSettings =
                UIUserNotificationSettings(types: [.alert, .badge, .sound], categories: nil)
            application.registerUserNotificationSettings(settings)
        }
        
        application.registerForRemoteNotifications()
    }
    
    @available(iOS 10.0, *)
    override func userNotificationCenter(_ center: UNUserNotificationCenter,
                                         willPresent notification: UNNotification,
                                         withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {

        let userInfo = notification.request.content.userInfo
        completionHandler([[.alert, .sound]])
    }
    
    @available(iOS 10.0, *)
    override func userNotificationCenter(_ center: UNUserNotificationCenter,
                                         didReceive response: UNNotificationResponse,
                                         withCompletionHandler completionHandler: @escaping () -> Void) {
        
        print("withCompletionHandler")
        completionHandler()
    }
    
    override func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
        print("didFailToRegisterForRemoteNotificationsWithError")
    }
    
    func application(application: UIApplication,
                     didRegisterForRemoteNotificationsWithDeviceToken deviceToken: NSData) {
        
        
        print("didRegisterForRemoteNotificationsWithDeviceToken")
    }
    
    func messaging(_ messaging: Messaging, didReceiveRegistrationToken fcmToken: String) {
        print("didReceiveRegistrationToken")
    }
    
    func messaging(_ messaging: Messaging, didReceive remoteMessage: MessagingRemoteMessage) {
            print("Received data message: \(remoteMessage.appData)")
    }
}

知道为什么没有为数据消息调用代表吗？？？

P.S: 当然我是在真正的 IOS 设备上测试

Answer 1

也许你没有在歌唱和能力的后台模式中启用“远程通知”。