swift - NSTimer 值不更新 UILabel？在 SWIFT

Question

我正在尝试使用 NSTimer.scheduledTimerWithTimeInterval 方法更新标签，尽管计时器工作正常但我的标签没有按预期更改，有人可以告诉我我做错了什么吗？代码:

class Questions: UIViewController, UITextFieldDelegate {

    var timerVal = 10
    var timerLbl :UILabel!
    var timer:NSTimer!

    override func viewDidLoad() {
        super.viewDidLoad()

      startTimer()
    }


    func timerLabel() {
        var timerLbl = UILabel(frame: CGRectMake(250, 20, 50, 50))
        timerLbl.text = "\(10)"
        timerLbl.textColor = UIColor.blackColor()
        timerLbl.font = UIFont(name: Font.FuturaBlack, size: 30)
        timerLbl.textAlignment = NSTextAlignment.Center

        view.addSubview(timerLbl)
    }

    func updateTimer(dt:NSTimer) {
        timerVal--
        if timerVal == 0{
           timerVal = 11
        }else if timerVal < 0{
            timer.invalidate()
        } else{
            println(timerString) //PRINTS CORRECT AS THE TIMER DECREASES BY ONE SECOND
            timerLbl.text = "\(timerVal)" //NOTHING HAPPENS ON THE LABEL
        }
    }

    func startTimer(){
        timer = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: Selector("updateTimer:"), userInfo: nil, repeats: true)
    }

}

Answer 1

永远不会调用创建 timerLbl 的函数 timerLabel。