带有重复TimeIntervalNotificationTrigger的数组中的随机元素

Question

当我单击按钮时，它应该每隔90秒从我的数组发送一个randomElement。但是它发送的总是一样。例如，第一个通知是“ A”，所有其他通知也是“ A”。但是我希望它们从数组中是随机的，我也想将实际的randomElement保存在另一个变量中。

class ViewController: UIViewController {

    var meinArray = ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "A", "B", "C", "D"]

    override func viewDidLoad() {
        super.viewDidLoad()

        authorize()
    }


    @IBAction func button_Tapped(_ sender: UIButton) {

        if let random = meinArray.randomElement(){
            addNotification(time: 90, body: random)
        }
    }


    let uncenter = UNUserNotificationCenter.current()

    func authorize(){

        uncenter.requestAuthorization(options: [.alert, .sound, .badge]) { (didAllow, error) in
            print(error ?? "No error")
        }
        configure()
    }

    func configure(){

        uncenter.delegate = self
    }

    func addNotification(time: TimeInterval, body: String){

        let content = UNMutableNotificationContent()
        content.body = body
        content.sound = .default

        let trigger = UNTimeIntervalNotificationTrigger(timeInterval: time, repeats: true)

        let request = UNNotificationRequest(identifier: "request", content: content, trigger: trigger)

        uncenter.add(request, withCompletionHandler: nil)
    }

}

Answer 1

它不起作用。我的代码：类ViewController：UIViewController {

var arrayMein = ["1", "2", "3", "4", "5", "6", "7", "8", "9"]

let unCenter = UNUserNotificationCenter.current()

override func viewDidLoad() {
    super.viewDidLoad()

    unCenter.requestAuthorization(options: [.alert, .sound, .badge]) { (didAllow, error) in
        print(error ?? "No error")
    }

    unCenter.delegate = self
}

@IBAction func button_Tapped(_ sender: UIButton) {

    Timer.scheduledTimer(timeInterval: 90, target: self, selector: #selector(showArray), userInfo: nil, repeats: true)
}


@objc func showArray() {
if let random = arrayMein.randomElement() {
    let content = UNMutableNotificationContent()
    content.body = random
    content.sound = .default

    let request = UNNotificationRequest(identifier: "request", content: content, trigger: nil)

    unCenter.add(request, withCompletionHandler: nil)
}

}

}

扩展名ViewController：UNUserNotificationCenterDelegate {

func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {

    print("will present")
}

func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {

    print("did receive")
}

}

Answer 2

尝试以下方法：

@IBAction func button_Tapped(_ sender: UIButton) {
    Timer.scheduledTimer(timeInterval: 90, target: self, selector: #selector(showArray), userInfo: nil, repeats: true)
}

@objc func showArray() {
    if let random = meinArray.randomElement() {
        let content = UNMutableNotificationContent()
        content.body = random
        content.sound = .default

        let request = UNNotificationRequest(identifier: "request", content: content, trigger: nil)

        uncenter.add(request, withCompletionHandler: nil)
    }
}

...

func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
    completionHandler( [.alert, .badge, .sound])
}

看起来像我们这样做：

if let random = meinArray.randomElement(){
    addNotification(time: 90, body: random)
}

然后添加到NotificationCenter，该回调将不会再次运行.randomElement（），而是仅采用第一个的元素，并且仅对其进行调用。