后台抓取请求和通知并非在所有情况下都有效

Question

在我的AppDelegate中，我添加了一个在我的Core Data上执行获取请求的方法，在某些情况下，我会显示通知...但是我看到有一些不推荐使用的方法。我尝试进行一些更改，但是：

• 当我杀死我的应用程序时，后台模式不起作用

• 当我的应用位于前台时，后台模式有效，但不显示通知

• 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，但我现在对类似的问题得到了很好的答案，请参阅Rob的答案

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这一点的提示。

另一个问题已经在评论中回答了：

看到这个 stackoverflow.com/questions/17044373/...对于为什么当你的应用处于前台时不显示通知的问题（因为应用必须显示通知本身） – Data Cosmos 1 月 13 日上午 10：49