后台获取请求和通知并非在所有情况下都有效

Question

在我的AppDelegate 中，我添加了一个方法来对我的Core Data 执行获取请求，并且在某些情况下我会显示一个通知...但我看到有一些已弃用的方法。我试图做一些改变，但是：

• 当我杀死我的应用程序时，后台模式不起作用

• 当我的应用在前台时，后台模式有效，但通知不显示

• 当我在后台运行我的应用程序时，一切正常

这是我的代码：

我想每次（每分钟）运行的方法：

func notification(){

    let appDel: AppDelegate = UIApplication.shared.delegate as! AppDelegate
    let context: NSManagedObjectContext = appDel.managedObjectContext
    var messageNotif:String? = nil

    do {

        let request = NSFetchRequest<NSFetchRequestResult>(entityName: "Leads")
        let predicate = NSPredicate(format: "statutSendLead=%@ OR statutSendSimulation=%@", "0", "0")
        request.predicate = predicate
        let results = try context.fetch(request)

        if results.count > 0 {
            if Reachability.isConnectedToNetwork() == false {

                messageNotif = "Votre demande n'a pas été envoyée, merci de vous connecter à internet."
            } else {

                Reachability.checkUrl(urlString:Configuration.MyVariables.url, finished: { isSuccess in


                    if isSuccess == false {
                        messageNotif = "Notre service d'enregistrement des demandes est temporairement indisponible, un renvoi sera effectué ultérieurement."
                    }
                })
            }
            */


            if (messageNotif != nil) {

                let identifier = self.stringWithUUID()


                if #available(iOS 10.0, *) {
                    let center = UNUserNotificationCenter.current()
                    center.requestAuthorization(options: [.alert, .sound]) { (granted, error) in

                        let content = UNMutableNotificationContent()

                        content.body = messageNotif!
                        content.sound = UNNotificationSound.default()
                        // Deliver the notification in five seconds.
                        let trigger = UNTimeIntervalNotificationTrigger.init(timeInterval: 5, repeats: false)
                        let request = UNNotificationRequest.init(identifier: "test", content: content, trigger: trigger)

                        // Schedule the notification.
                        let center = UNUserNotificationCenter.current()

                        UNUserNotificationCenter.current().removeAllPendingNotificationRequests()
                        UNUserNotificationCenter.current().add(request) {(error) in
                            if let error = error {
                                print(error)
                            }
                        }
                    }
                } else {
                    let notification = UILocalNotification()
                    notification.alertBody = messageNotif
                    notification.fireDate = NSDate() as Date
                    notification.soundName = UILocalNotificationDefaultSoundName
                    UIApplication.shared.scheduleLocalNotification(notification)
                }
            }
        }

        /* else {
         timerNotification.invalidate()
         } */

    } catch {
        print(error)
    }
}

其他方法：

var window: UIWindow?
var timerUploadData:Timer!
var timerNotification:Timer!
var test:Timer!

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

    UIApplication.shared.setMinimumBackgroundFetchInterval(
        UIApplicationBackgroundFetchIntervalMinimum)

    let userDefaults = UserDefaults.standard

    if userDefaults.object(forKey: "ApplicationUniqueIdentifier") == nil {
        let UUID = Foundation.UUID().uuidString
        userDefaults.set(UUID, forKey: "ApplicationUniqueIdentifier")
        userDefaults.synchronize()
    }

    Thread.sleep(forTimeInterval: 3.0)
    window = UIWindow(frame: UIScreen.main.bounds)
    let containerViewController = ContainerViewController()
    window!.rootViewController = containerViewController
    window!.makeKeyAndVisible()


    if #available(iOS 10.0, *){

        application.registerUserNotificationSettings(UIUserNotificationSettings(types: [.badge, .sound, .alert], categories: nil))
        timerNotification = Timer.scheduledTimer(timeInterval: 60 * 1, target: self, selector: #selector(AppDelegate.notification), userInfo: nil, repeats: true)

    }
    else { //If user is not on iOS 10 use the old methods we've been using
        let notificationSettings = UIUserNotificationSettings(
            types: [UIUserNotificationType.badge, UIUserNotificationType.alert, UIUserNotificationType.sound], categories: nil)
        timerNotification = Timer.scheduledTimer(timeInterval: 60 * 1, target: self, selector: "notification", userInfo: nil, repeats: true)
        application.registerUserNotificationSettings(notificationSettings)
    }

    registerPushNotifications()

    return true
}

func application(_ application: UIApplication, performFetchWithCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
    notification()
}


func application(_ application: UIApplication, didRegister notificationSettings: UIUserNotificationSettings) {
    if notificationSettings.types != UIUserNotificationType() {
        application.registerForRemoteNotifications()
    }
}

func registerPushNotifications() {
    DispatchQueue.main.async {
        let settings = UIUserNotificationSettings(types: [.badge, .sound, .alert], categories: nil)
        UIApplication.shared.registerUserNotificationSettings(settings)
    }
}

func stringWithUUID() -> String {
    let uuidObj = CFUUIDCreate(nil)
    let uuidString = CFUUIDCreateString(nil, uuidObj)!
    return uuidString as String
}

Answer 1

虽然这是一个老问题，但我现在在类似问题上得到了很好的答案，请参阅the answer from Rob

这是一个可能的答案，为什么当你杀死你的应用程序时你的后台模式不起作用，甚至是关于如何测试它的提示。

cmets 中已经回答了另一个问题：

请参阅此 stackoverflow.com/questions/17044373/… 了解您的问题为什么在您的应用处于前台时不显示通知（因为应用必须显示通知本身） – data cosmos 1 月 13 日 10:49