swift - 每毫秒更新一次进度条

Question

我希望我的进度栏每毫秒更新一次。我该怎么做？目前，它每秒更新一次，这不是我想要的。

编辑:抱歉，我忘了提及，我仍然希望计时器标签每秒更新一次(因此它会按秒而不是毫秒减少:10、9、8)，同时每毫秒或每 25 次更新进度条第二。

代码:

 progressBar.transform = progressBar.transform.scaledBy(x: 1, y: 5)
        progressBar.layer.cornerRadius = 5
        progressBar.clipsToBounds = true
        progressBar.layer.sublayers![1].cornerRadius = 5
        progressBar.subviews[1].clipsToBounds = true

func startTimer() {

    timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(timerUpdate), userInfo: nil, repeats: true)

}

@objc func timerUpdate() {

    if timeRemaining <= 0 {
        progressBar.setProgress(Float(0), animated: false)
        bonusTimerLabel.text = "0"
        bonusTimerLabel.textColor = UIColor(red: 186/255, green: 16/255, blue: 16/255, alpha: 1)

    } else {
        progressBar.setProgress(Float(timeRemaining)/Float(10), animated: false)
        timeRemaining -= 1
        bonusTimerLabel.text = "\(timeRemaining)"
    }

Answer 1

不建议每毫秒使用timer触发一个函数，引用:https://stackoverflow.com/a/30983444/8447312

因此，为了安全起见，您可以每 50 毫秒触发一次计时器函数并更新进度条。但这不应该太明显。

还要确保 timeRemaining 是 Double，然后尝试:

func startTimer() {

    timer = Timer.scheduledTimer(timeInterval: 0.050, target: self, selector: #selector(timerUpdate), userInfo: nil, repeats: true)

}

@objc func timerUpdate() {

    if timeRemaining <= 0 {
        progressBar.setProgress(Float(0), animated: false)
        bonusTimerLabel.text = "0"
        bonusTimerLabel.textColor = UIColor(red: 186/255, green: 16/255, blue: 16/255, alpha: 1)

    } else {
        progressBar.setProgress(Float(timeRemaining)/Float(20), animated: false)
        timeRemaining -= 0.050
        bonusTimerLabel.text = "\(Int(timeRemaining))"
    }