Ios 在应用程序处于后台时从默认通知中心接收通知

在我的应用程序中，我使用

fetchAssets（with:）

获取相机滚动的内容。为了接收更改消息，我已使用照片库的

register（:）

方法注册了我的观察者。我的观察者对

PHPhotoLibraryChangeObserver

协议感到欣慰。所以当图书馆发生变化时，我应该得到通知。我想要支持的场景是，当我运行我的应用程序时，我进入后台，然后打开相机应用程序，拍照，然后返回到我的应用程序。当我的应用程序返回前台时，是否可能在后台收到更改通知

是的，您可以创建LocalNotification，并在应用程序进入后台并返回前台时触发它

func scheduleNotification(timeInter : TimeInterval) {
        let content = UNMutableNotificationContent()
        let userActions = "User Actions"
        content.title = "Title "
        content.body = "Body"
        content.sound = UNNotificationSound.init(named: 
        content.categoryIdentifier = userActions
        content.userInfo = ["MID" : RANDOM_ID, "timeInterval" : String(timeInter)]
        let trigger = UNTimeIntervalNotificationTrigger(timeInterval: timeInter, repeats: false)
        let identifier = String(timeInter)


        let request = UNNotificationRequest(identifier: identifier, content: content, trigger: trigger)
        print(request.identifier)
        notificationCenter.add(request) { (error) in
            if let error = error {

            }
        }
        //  let snoozeAction = UNNotificationAction(identifier: "Snooze", title: "Snooze", options: [])
        let deleteAction = UNNotificationAction(identifier: "Delete", title: "Delete", options: [.destructive])
        let category = UNNotificationCategory(identifier: userActions, actions: [deleteAction], intentIdentifiers: [], options: [])
        notificationCenter.setNotificationCategories([category])
    }

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是的，你们可以创建LocalNotification，当应用程序在后台运行，在前台返回时触发它

func scheduleNotification(timeInter : TimeInterval) {
        let content = UNMutableNotificationContent()
        let userActions = "User Actions"
        content.title = "Title "
        content.body = "Body"
        content.sound = UNNotificationSound.init(named: 
        content.categoryIdentifier = userActions
        content.userInfo = ["MID" : RANDOM_ID, "timeInterval" : String(timeInter)]
        let trigger = UNTimeIntervalNotificationTrigger(timeInterval: timeInter, repeats: false)
        let identifier = String(timeInter)


        let request = UNNotificationRequest(identifier: identifier, content: content, trigger: trigger)
        print(request.identifier)
        notificationCenter.add(request) { (error) in
            if let error = error {

            }
        }
        //  let snoozeAction = UNNotificationAction(identifier: "Snooze", title: "Snooze", options: [])
        let deleteAction = UNNotificationAction(identifier: "Delete", title: "Delete", options: [.destructive])
        let category = UNNotificationCategory(identifier: userActions, actions: [deleteAction], intentIdentifiers: [], options: [])
        notificationCenter.setNotificationCategories([category])
    }

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我应该为此请求用户权限吗？我应该为此请求用户权限吗？