Invalidating NSTimer

Question

I have 4 NSTimers objects in my app , that make requests to a rest URL every few seconds.

On clicking of a particular button I want to stop the timer so that it stops polling and on click of another button I want to resume polling.

I have tried invalidate for all timers but does not work.

NOTE: All timers are in different class and I'm trying to invalidate the timers in another class Any help will be appreciated , thank you.

class NotificationViewController:UIViewController {
    var timer:NSTimer?
    getEvents(){
    if((timer == nil)) {
        timer = NSTimer.scheduledTimerWithTimeInterval(20.0, target: self, selector: Selector("getEvents"), userInfo: nil, repeats: true)
    }
  }
}

In another class I'm doing this on click of a button

class Menu:UIViewController {

    @IBAction func buttonTapped(sender: UIButton) {
        self.notify.timer?.invalidate()
        self.notify.timer = nil
    }
}

Answer 1

Try to create a separate NotificationTimer class and used its shared object all over the project like this way.

class NotificationTimer: NSObject {

    var timer1: NSTimer?
    var timer2: NSTimer?
    var timer3: NSTimer?
    var timer4: NSTimer?

    static let sharedManager = NotificationTimer()

    func getEvents(){
        print("Fired")
        if (timer1 == nil){
            timer1 = NSTimer.scheduledTimerWithTimeInterval(20.0, target: self, selector: Selector("methodYouWantToCall"), userInfo: nil, repeats: true)
        }
    }    
}

Now call this timer1 object inside any ViewController like this way.

let notificationTimer = NotificationTimer.sharedManager
notificationTimer.timer1?.invalidate()

Or call that method like this way

NotificationTimer.sharedManager().getEvents()