我试着

var timer = NSTimer()
timer(timeInterval: 0.01, target: self, selector: update, userInfo: nil, repeats: false)

但是,我得到了一个错误

'(timeInterval: $T1, target: ViewController, selector: () -> (), userInfo: NilType, repeats: Bool) -> $T6' is not identical to 'NSTimer'

当前回答

SimpleTimer (Swift 3.1)

Why?

这是一个简单的定时器类在swift,使您能够:

局部作用域定时器 证明 一个衬垫 使用常规回调

用法:

SimpleTimer(interval: 3,repeats: true){print("tick")}.start()//Ticks every 3 secs

代码:

class SimpleTimer {/*<--was named Timer, but since swift 3, NSTimer is now Timer*/
    typealias Tick = ()->Void
    var timer:Timer?
    var interval:TimeInterval /*in seconds*/
    var repeats:Bool
    var tick:Tick

    init( interval:TimeInterval, repeats:Bool = false, onTick:@escaping Tick){
        self.interval = interval
        self.repeats = repeats
        self.tick = onTick
    }
    func start(){
        timer = Timer.scheduledTimer(timeInterval: interval, target: self, selector: #selector(update), userInfo: nil, repeats: true)//swift 3 upgrade
    }
    func stop(){
        if(timer != nil){timer!.invalidate()}
    }
    /**
     * This method must be in the public or scope
     */
    @objc func update() {
        tick()
    }
}

其他回答

斯威夫特5

我个人更喜欢带块闭包的定时器:

    Timer.scheduledTimer(withTimeInterval: 1, repeats: false) { (_) in
       // TODO: - whatever you want
    }

在iOS 10中,还有一个新的基于块的定时器工厂方法,它比使用选择器更干净:

    _ = Timer.scheduledTimer(withTimeInterval: 5, repeats: false) { timer in
        label.isHidden = true
    }

SimpleTimer (Swift 3.1)

Why?

这是一个简单的定时器类在swift,使您能够:

局部作用域定时器 证明 一个衬垫 使用常规回调

用法:

SimpleTimer(interval: 3,repeats: true){print("tick")}.start()//Ticks every 3 secs

代码:

class SimpleTimer {/*<--was named Timer, but since swift 3, NSTimer is now Timer*/
    typealias Tick = ()->Void
    var timer:Timer?
    var interval:TimeInterval /*in seconds*/
    var repeats:Bool
    var tick:Tick

    init( interval:TimeInterval, repeats:Bool = false, onTick:@escaping Tick){
        self.interval = interval
        self.repeats = repeats
        self.tick = onTick
    }
    func start(){
        timer = Timer.scheduledTimer(timeInterval: interval, target: self, selector: #selector(update), userInfo: nil, repeats: true)//swift 3 upgrade
    }
    func stop(){
        if(timer != nil){timer!.invalidate()}
    }
    /**
     * This method must be in the public or scope
     */
    @objc func update() {
        tick()
    }
}

在Swift 3中使用@objc:

func startTimerForResendingCode() {
    let timerIntervalForResendingCode = TimeInterval(60)
    Timer.scheduledTimer(timeInterval: timerIntervalForResendingCode,
                         target: self,
                         selector: #selector(timerEndedUp),
                         userInfo: nil,
                         repeats: false)
}




@objc func timerEndedUp() {
    output?.timerHasFinishedAndCodeMayBeResended()
}

更新到Swift 4,利用userInfo:

class TimerSample {

    var timer: Timer?

    func startTimer() {
        timer = Timer.scheduledTimer(timeInterval: 5.0,
                                     target: self,
                                     selector: #selector(eventWith(timer:)),
                                     userInfo: [ "foo" : "bar" ],
                                     repeats: true)
    }

    // Timer expects @objc selector
    @objc func eventWith(timer: Timer!) {
        let info = timer.userInfo as Any
        print(info)
    }

}