Swift 如何停止 NSTimer.scheduledTimerWithTimeInterval

我该如何让计时器停止运行？不是停顿，而是停下来.

import UIKit

class LastManStandingViewController: UIViewController {    

@IBOutlet weak var timeLabel: UILabel!
@IBOutlet weak var timeTextbox: UITextField!
@IBOutlet weak var startButton: UIButton!
@IBOutlet weak var stopButton: UIButton!

var myCounter = 0
var myTimer : NSTimer = NSTimer()

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    timeLabel.text = String(myCounter)
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

func startTimer(){
    myTimer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: Selector("updateTimer"), userInfo: nil, repeats: true)
    println("func startTimer")
}

func stopTimer(){
    myTimer.invalidate()
    myCounter = 0
    timeLabel.text = String(myCounter)
    println("func stopTimer")
}

func updateTimer(){
    timeLabel.text = String(myCounter++)
    println("func updateTimer")
}
@IBAction func startButton(sender: AnyObject) {
    startTimer()
}
@IBAction func stopButton(sender: AnyObject) {
    stopTimer()
}

}

我可以启动计时器，但当我按下停止按钮时，它会自动重置，并再次开始计数.它不会停止.

成功了.我的项目出了问题！通过移除按钮并重新添加来修复.看起来我有个复制品什么的.