Question

我有一个标签，以12小时格式显示当前时间。

但是，每次分钟/小时更改时，它都不会更新/刷新时间。

我需要它在时间变化时自动将标签更改为当前时间。

Answer 1

Swift 3解决方案

class ViewController {

@IBOutlet weak var timeLabel: UILabel!
var timer: Timer?

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

将以下代码替换为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
}

}

Swift - 显示时间的更新/刷新标签

2 个答案: