How to call function on time? Also How to Call only once time in swift 3?

Question

i need to call one function one time only, so how can possible to call function only one time like after 3 seconds?

Possible duplicate of [How to program a delay in Swift 3](https://stackoverflow.com/questions/38031137/how-to-program-a-delay-in-swift-3) — Dharma, Jun 28 '17 at 07:14

Ketan Parmar · Answer 1 · 2017-06-28T07:36:12.720

1

You can do something like,

DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
   yourFunction() // call your functin here
}

You can also use DispatchQueue.global().asyncAfter if you don't want to perform your task on main thread!

And refer this post to manage it one time only!

edited Jun 28 '17 at 07:36

answered Jun 28 '17 at 06:55

Ketan Parmar

27,092
9
50
75

its call multiple times, repeating calling function after every 3 second – Deepak Tagadiya Jun 28 '17 at 07:14
you should refer [this post](https://stackoverflow.com/questions/37886994/dispatch-once-in-swift-3) – Ketan Parmar Jun 28 '17 at 07:35

score 0 · Answer 2 · answered Jun 28 '17 at 07:06

private let _onceToken = NSUUID().uuidString

DispatchQueue.once(token: _onceToken) {
     print( "Do This Once!" )
     DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
         yourFunction() // call your functin here
     }
}

It will execute your method only once and delay your method for 3 seconds.

score 0 · Accepted Answer · answered Jul 19 '17 at 09:29

For start timer:

  var timerUpdateArray:Timer!
  func callTimer(){
        self.timerUpdateArray = Timer.scheduledTimer(timeInterval: 1, 
        target: self, selector: #selector(yourFunc), 
        userInfo: nil, repeats: true)
   }

For stop timer:

 self.timerUpdateArray.invalidate()

How to call function on time? Also How to Call only once time in swift 3?

3 Answers3