How initialize a Timer inside a custom class in Swift? [duplicate]


This question already has an answer here:

<ul><li> <a href="/questions/36962854/swift-wants-argument-of-selector-to-be-exposed-to-objective-c" dir="ltr" rel="nofollow">Swift wants argument of #selector to be exposed to Objective-C</a> <span class="question-originals-answer-count"> 3 answers </span> </li> </ul>

I make a simple cronometer app, but, now I want make it better, and I would like to write a class for the cronometer control:

class Cronometer{ private var counter:Int = 0 private var timer:Timer = Timer() private var state:Bool = true func initCronometer(){ if self.state{ self.timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: Selector("onTick"), userInfo: nil, repeats: true) }else{ self.timer.invalidate() } self.state = !self.state } func onTick(){ self.counter += 1 print(self.counter) } }

But the selector parameter it's not working inside the class with a custom method. I don't want it inside the ViewController, like as I maded before.

I try with

self.timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: Selector(("onTick")), userInfo: nil, repeats: true)


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

...but still not working

So, whats it's the best way to assign a class method as selector in the Timer initializer?

Thanks a lot!


Timer is an overlay type for the Foundation type NSTimer, which uses Objective-C messaging to invoke the timer target. Therefore the target method must be available for use in Objective-C.

You have the following options:

<ul><li>Mark only the onTick() method with @objc (as Matt already said).</li> <li>Make the Cronometer class a subclass of NSObject.</li> <li>

On iOS 10/macOS 10.12 you can use the newer block-based timer API:

self.timer = Timer.scheduledTimer(withTimeInterval: 1, repeats: true) { _ in self.onTick() } </li> </ul>


Declare @objc func onTick() and all will be well.


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