NSTimer - 如何在Swift中延迟

Question

I have a problem with delaying computer's move in a game.

I've found some solutions but they don't work in my case, eg

var delay = NSTimer.scheduledTimerWithTimeInterval(4, target: self, selector: nil, userInfo: nil, repeats: false)

I tried to use this with function fire but also to no effects.

What other possibilities there are?

Answer 1

Swift 3

With GCD:

let delayInSeconds = 4.0
DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + delayInSeconds) {

    // here code perfomed with delay

}

or with a timer:

func myPerformeCode() {

   // here code to perform
}
let myTimer : Timer = Timer.scheduledTimer(timeInterval: 4, target: self, selector: #selector(self.myPerformeCode), userInfo: nil, repeats: false)

Swift 2

With GCD:

let seconds = 4.0
let delay = seconds * Double(NSEC_PER_SEC)  // nanoseconds per seconds
let dispatchTime = dispatch_time(DISPATCH_TIME_NOW, Int64(delay))

dispatch_after(dispatchTime, dispatch_get_main_queue(), {

   // here code perfomed with delay

})

or with a timer:

func myPerformeCode(timer : NSTimer) {

   // here code to perform
}
let myTimer : NSTimer = NSTimer.scheduledTimerWithTimeInterval(4, target: self, selector: Selector("myPerformeCode:"), userInfo: nil, repeats: false)

Answer 2

With Swift 4.2

With Timer You can avoid using a selector, using a closure instead:

    Timer.scheduledTimer(withTimeInterval: 1.0, repeats: false) { (nil) in
        // Your code here
    }

Keep in mind that Timer is toll-free bridged with CFRunLoopTimer , and that run loops and GCD are two completely different approaches.... e

Answer 3

In swift we can delay by using Dispatch_after.

SWift 3.0 :-

DispatchQueue.main.asyncAfter(deadline: .now()+4.0) {

        alert.dismiss(animated: true, completion: nil)
    }

Answer 4

How about using Grand Central Dispatch?

https://developer.apple.com/library/ios/documentation/Performance/Reference/GCD_libdispatch_Ref/index.html

Valfer has shown you how