NSTimer doesn't work on swift

Question

I wrote this code to use a Timer inside of a View Controller:

var timer:NSTimer!
override func viewDidLoad() {
    super.viewDidLoad()
    timer = NSTimer(timeInterval: 2, target: self, selector: "goTakingPhoto", userInfo: nil, repeats: false)
    timer.fire()
    // Do any additional setup after loading the view.
}
 func goTakingPhoto(){
   // doSomething
}

But the function goTakingPhoto is invoked immediately, not after 2 seconds. Can anyone help me? Many thanks.

There's an alternate option for you, if you're just looking to create a delay when the view loads, an `NSTimer` is likely overkill. You can use GCD to add a delay without the `NSTimer` overhead: `dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(2.0 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) { self.goTakingPhoto() }` It looks a lot more complicated than it is, and I use a macro (Thanks to [Dash][1]) so I don't actually have to type it out each time. [1]: https://itunes.apple.com/us/app/dash-3-api-docs-snippets/id449589707?mt=12&uo=4&at=11lMGu — Dave Wood, Jul 08 '15 at 01:37

Hayley Guillou · Answer 1 · 2015-07-08T01:25:42.583

3

Try this:

override func viewDidLoad() {
    super.viewDidLoad()
    var timer = NSTimer.scheduledTimerWithTimeInterval(2, target: self, selector: Selector("goTakingPhoto"), userInfo: nil, repeats: false)}
}

func goTakingPhoto() {
   // doSomething
}

edited Jul 08 '15 at 01:25

answered Jul 08 '15 at 01:22

Hayley Guillou

3,953
4
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1

Yeah, he should also remove the `timer.fire()` – Kametrixom Jul 08 '15 at 01:24

score 0 · Answer 2 · edited May 23 '17 at 10:27

0

I found it works with NSTimer.scheduledWithTimeInterval(...). And you don't have to add timer.fire() otherwise the func will be invoked imediately

Reference here

edited May 23 '17 at 10:27

Community

1
1

answered Jul 08 '15 at 01:31

lwiu

179
1
9

NSTimer doesn't work on swift

2 Answers2