[iOSアプリ開発][Xcode 8] ストップウォッチを実装する

 1    @IBOutlet weak var StopWatchLabel: UILabel!
 2    
 3    
 4    var timer = Timer()
 5    var seconds:Int = 0
 6    var fractions:Int = 0
 7    var stopwatchString: String = ""
 8    var startStopWatch:Bool = true
 9    
10    
11    @IBAction func StartStopButton(_ sender: AnyObject) {
12        if startStopWatch == true {
13            timer = Timer.scheduledTimer(timeInterval: 0.01, target: self, selector: #selector(ThirdViewController.updateStopwatch), userInfo: nil, repeats: true)
14            startStopWatch = false
15        }else {
16            timer.invalidate()
17            startStopWatch = true
18        }
19    }
20    
21    func updateStopwatch() {
22        fractions += 1
23        if fractions == 100 {
24            seconds += 1
25            fractions = 0
26        }
27        let fractionsString = fractions > 9 ? "\(fractions)" : "0\(fractions)"
28        let secondsString = seconds > 9 ? "\(seconds)" : "0\(seconds)"
29        
30        stopwatchString = "\(secondsString).\(fractionsString)"
31        StopWatchLabel.text = stopwatchString
32    }

1@IBAction func Reset(_ sender: AnyObject) {
2        fractions = 0
3        StopWatchLabel.text = "00.00"
4    }