Swift – 显示时间的更新/刷新标签

我有一个以12小时格式显示当前时间的标签。

但是，它不会每分钟/小时变化更新/刷新时间。

我需要它自动更改标签到当前时间，当时间改变。

Answer 1

Swift 3解决scheme

class ViewController { @IBOutlet weak var timeLabel: UILabel! var timer: NSTimer? let formatter: DateFormatter = { let tmpFormatter = DateFormatter() tmpFormatter.dateFormat = "hh:mm a" return tmpFormatter }() override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view, typically from a nib. timer = Timer.scheduledTimer(timeInterval: 60, target: self, selector: #selector(self.getTimeOfDate), userInfo: nil, repeats: true) } override func viewWillDisappear(_ animated: Bool) { super.viewWillDisappear(animated) timer?.invalidate() } func getTimeOfDate() { var curDate = Date() timeLabel.text = formatter.string(from: curDate) } 

Answer 2

将以下代码replace为ViewController代码，然后将iboutlet连接到showTimeLbl

 class ViewController: UIViewController { @IBOutlet weak var showTimeLbl: UILabel! var timeCount:Int = 0 var timer:Timer! override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view, typically from a nib. if(timer != nil) { timer.invalidate() } timer = Timer(timeInterval: 1.0, target: self, selector: #selector(ViewController.timerDidFire), userInfo: nil, repeats: true) RunLoop.current.add(timer, forMode: RunLoopMode.commonModes) } func timerDidFire() { timeCount += 1 showTimeLbl.text = NSString(format: "%02d:%02d:%02d", timeCount/3600,(timeCount/60)%60,timeCount%60) as String } override func viewWillDisappear(_ animated: Bool) { super.viewWillDisappear(true) timer?.invalidate() timer = nil } 

}