Pause NSTimer when app goes to background

Question

I have the following in my touchesBegan function in my GameScene so that the timer only starts when the user touches a certain sprite:

let start = SKAction.runBlock({
    NSTimer.scheduledTimerWithTimeInterval(0.1, target: self, selector: "printDuration:", userInfo: NSDate(), repeats: true)
})

tapToStartNode.runAction(start)

and the following function:

func printDuration(timer: NSTimer) {
    if self.view?.paused == false {
        guard let userInfo = timer.userInfo else {
            return
        }
        guard let startDate = userInfo as? NSDate else {
            return
        }
        let duration = NSDate().timeIntervalSinceDate(startDate)
        currentTime = NSDate().timeIntervalSinceDate(startDate)
        currentTimeValueLabel.text = "\(NSString(format:"%3.2f", duration))"
    }
}

However, when applicationDidEnterBackground or applicationWillResignActive the timer is not paused and continues to run when the app is in the backgorund. How do I make it stop?

Answer 1

Here a tips you can use for your problem

You can use func applicationDidEnterBackground(_ application: UIApplication) or func applicationWillResignActive(_ application: UIApplication) on AppDelegate

Access your controller by initialize rootViewController example :

let vc = self.window?.rootViewController as? ViewController

Then you can access your function (make sure function is on public state)

vc.pauseTimer() (customize based on your situation)

Hope it will be helpful