NSTimer - how to delay in Swift

问题:

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, e.g.

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?

回答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)

回答2:

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)
    }

回答3:

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