Pausing timer when app is in background state Swift

Question

My ViewController.swift

func startTimer() {
    timer = NSTimer().scheduleTimerWithTimerInvterval(1.0,target: self,selctor: Selector(\"couting\"),userinfo: n         


        

Answer 1

Updated Answer for Swift 5:

NotificationCenter.default.addObserver
              (self,
               selector: #selector(myObserverMethod),
               name:UIApplication.didEnterBackgroundNotification, object: nil)

@objc func myObserverMethod(){
    print("Write Your Code Here")
}