How can I pause and resume NSTimer.scheduledTimerWithTimeInterval in swift?

Question

I\'m developing a game and I want to create a pause menu. Here is my code:

self.view?.paused = true

but NSTimer.scheduledTimerWithT

Answer 1

To start

timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(ViewController.action), userInfo: nil, repeats: true)

To pause

timer.invalidate()

To reset

time += 1
label.text = String(time)

'label' is the timer on output.

Answer 2

To stop it

  time3.invalidate() 

To start it again

  time3.fire()

Answer 3

Even though the solutions exposed here are good, I thought an important insight was missing. Like a lot of people here explained, timer invalidate() and recreate is the best option. But one could argue that you could do something like this:

var paused:Bool

func timerAction() {
    if !paused {
        // Do stuff here
    }
}

is easier to implement, but it will be less efficient.

For energy impact reasons, Apple promotes avoiding timers whenever possible and to prefer event notifications. If you really need to use a timer, you should implement pauses efficiently by invalidating the current timer. Read recommendations about Timer in the Apple Energy Efficiency Guide here: https://developer.apple.com/library/content/documentation/Performance/Conceptual/EnergyGuide-iOS/MinimizeTimerUse.html