Swift：当应用程序处于非活动状态时，willPresent通知完成处理程序将无法运行

Question

当我的应用程序处于非活动状态时发送远程推送通知时，将显示警报，但未触发完成块中的其余代码（对“ doSomething（）”的调用）。在打开应用程序时会触发，但我仍然无法弄清楚为什么在提示仍然显示的情况下，当应用程序处于非活动状态时它不会显示。

我将Firebase用于后端

我的willPresent方法：

func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification,
                            withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
    let userInfo = notification.request.content.userInfo

    doSomething("willPresent notification")

    // Change this to your preferred presentation option
    completionHandler([.alert])
}

doSomething（）：

func doSomething(_ senderMethod: String) {
    if let userId = Auth.auth().currentUser?.uid {
        let userRef = Database.database().reference().child("Users").child(userId)
        let someValue = ["sent": senderMethod] as [String : AnyObject]

        userRef.updateChildValues(someValue)
    }
}

JSON有效载荷：

{
    "to": deviceId,
    "notification": {
                    "body": "test body",
                    "title": "Test",
                    "sound": "default"
                    },
    "priority": "high"
}

didFinishLaunching：

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    FirebaseApp.configure()
    Messaging.messaging().delegate = self
    setPushNotifications(application)

    return true
}

func setPushNotifications(_ application: UIApplication) {
    if #available(iOS 10.0, *) {
        // For iOS 10 display notification (sent via APNS)
        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()
}