swift - 在特定时间运行计时器(快速)

Question

我有一个应用程序，它从用户那里获取时间和时间间隔，并在那个时间开始倒计时。当我尝试在我拥有的时间启动计时器时，它吓坏了并且无法正常工作。

这是运行定时器的函数:

 func runTimer(){

    let timer = Timer(fireAt: firstMealTime, interval: 1, target: self, selector: #selector(updateTimer), userInfo: nil, repeats: true)
    RunLoop.main.add(timer, forMode: .commonModes)
}

这是 updateTimer 函数:

  if seconds < 1 {
        timerRepeat! -= 1
        updateMealLeftLabel(numberOfMeal: timerRepeat)
        resetTimer()
    }else{
        seconds -= 1
        updateTimerLabel()
    }

提前致谢!

Answer 1

您可以像这样检查您的计时器定义:

var seconds = YourCountdownValue // (in seconds) for example 100 seconds.

func runTimer(){
   firstMealTime = Date().addingTimeInterval(10.0) // This line is for testing. Countdown will be start in 10 seconds.
   let timer = Timer(fireAt: firstMealTime, interval: 1, target: self, selector: #selector(updateTimer), userInfo: nil, repeats: true)
   RunLoop.main.add(timer, forMode: .commonModes)
}

func updateTimer() {
    if seconds < 1 {
       timerRepeat! -= 1
       updateMealLeftLabel(numberOfMeal: timerRepeat)
       print("finished") //for testing
       resetTimer()
    }else{
       seconds -= 1
       print(seconds) //for testing
       updateTimerLabel()
   }
}