当应用程序处于后台状态 Swift 时暂停计时器 [英] Pausing timer when app is in background state Swift

问题描述

我的 ViewController.swift

My ViewController.swift

func startTimer() {
    timer = NSTimer().scheduleTimerWithTimerInvterval(1.0,target: self,selctor: Selector("couting"),userinfo: nil, repeats: true)
}

func pauseTimer() {
    timer.invalidate()
    println("pausing timer")
}

这是 appDelegate.swift

and this is appDelegate.swift

func applicateWillResignActive(application: UIApplication) {
    viewController().pauseTimer()
    println("closing app")
}

它正在打印暂停计时器和关闭应用，但当我再次打开时，我看到它从未暂停.我该如何正确操作?

It is printing pausing timer and closing app but when I open again I see it never paused. How do I do it correctly?

推荐答案

你必须设置一个观察者在应用程序进入后台时监听.在 ViewController 的 viewDidLoad() 方法中添加以下行.

You have to set an observer listening to when the application did enter background. Add the below line in your ViewController's viewDidLoad() method.

NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("myObserverMethod:"), name:UIApplicationDidEnterBackgroundNotification, object: nil)

添加下面的函数来接收通知.

Add the below function to receive the notification.

func myObserverMethod(notification : NSNotification) {
    println("Observer method called")

    //You may call your action method here, when the application did enter background.
    //ie., self.pauseTimer() in your case.
}

快乐编码！！！

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