Swift - UNUsernotification 检查 BadgeNumberIcon 中的更改 [英] Swift - UNUsernotification checking changes in BadgeNumberIcon

问题描述

我想在标签中显示徽章编号的值.

I Would like to display the value of the badge number in a label.

到目前为止，我已经把所有东西都放在了我的 viewWillAppear 中.因此，每次加载控制器时，都会分配变量.代码如下:

So far i've put everything in my viewWillAppear. So every time the controller is loaded the variable is assigned. Here's the code:

var deliveredNotif = Int()

 override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(true)
deliveredNotif = UIApplication.shared.applicationIconBadgeNumber
myBadgeLabel.text = "\(deliveredNotif)"
}

我的问题是:如果控制器处于活动状态并且 viewWillAppear 已被调用，我如何更新 DeliverNotif?意思是如果我在控制器中，有没有办法触发一个函数，它会在每次 applicationIconBadgeNumber 的值改变时更新 DeliverNotif 的值?

My question is: How can i update deliveredNotif if the controller is active and so viewWillAppear is already been called? Meaning if I am in the controller is there a way to trigger a func which will update the value of deliveredNotif every time the value of applicationIconBadgeNumber is changed?

谢谢！

-------更新----我的解决方案我创建了一个常量变量:var iconBadgeNumber = NSNumber()

-------UPDATE----MY SOLUTION I created a constant variable: var iconBadgeNumber = NSNumber()

在我的 Appdelegate 中:

in my Appdelegate i have:

func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
    completionHandler([.alert, .badge])
    NotificationCenter.default.post(name: NSNotification.Name(rawValue: "applicationIconBadgeNumber"), object: nil)
    iconBadgeNumber = UIApplication.shared.applicationIconBadgeNumber + 1 as NSNumber
}

然后在我的控制器中:

override func viewDidLoad() {
    super.viewDidLoad()
 NotificationCenter.default.addObserver(self, selector: #selector(updateIconBadgeNumber), name: NSNotification.Name(rawValue: "applicationIconBadgeNumber"), object: nil)


}

@objc func updateIconBadgeNumber() {
    if iconBadgeNumber == 0 {
        print("zero")
    } else {
    print("there unread notification")
    }
}

推荐答案

您可以将您的 UIViewController 设置为关键路径applicationIconBadgeNumber"的观察者:

You can set your UIViewController as an observer for the key path "applicationIconBadgeNumber":

首先注册远程通知.在您的 didFinishLaunchingWithOptions 函数中，添加:

First register for remote notifications. In your didFinishLaunchingWithOptions function, add:

    let center = UNUserNotificationCenter.current()
    center.requestAuthorization(options: [.alert, .badge, .sound]) { _, _ in
        DispatchQueue.main.async {
            application.registerForRemoteNotifications()
        }
    }

不要忘记在文件顶部添加:import UserNotifications

don't forget to add also: import UserNotifications on the top of your file

然后在您的 viewDidLoad 中添加:

Then add in your viewDidLoad:

UIApplication.shared.addObserver(self, forKeyPath: "applicationIconBadgeNumber", options: .new, context: nil)

然后，覆盖observeValue函数:

Then, override the observeValue function:

    override func observeValue(forKeyPath keyPath: String?,
                                        of object: Any?,
                                           change: [NSKeyValueChangeKey : Any]?,
                                          context: UnsafeMutableRawPointer?) {
        if keyPath == "applicationIconBadgeNumber" {
            deliveredNotif = UIApplication.shared.applicationIconBadgeNumber
            myBadgeLabel.text = "\(deliveredNotif)"
        }
    }

这篇关于Swift - UNUsernotification 检查 BadgeNumberIcon 中的更改的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！