ios - 计时器无法正常工作，Swift

Question

我正在尝试让计时器计数向上我按住按钮的秒数。(按住以录制视频)它无法正常工作......有时它会跳过秒数& 有时只是卡住然后加速 catch ......我真的需要你的帮助来解决这个问题，我需要计时器尽可能流畅和恒定，谢谢。

//Timer Variables:
    var recordingCounter : Timer!
    var minutes: Int = 0
    var seconds: Int = 0
    var counterString : String = ""

func longTap(_ sender: UIGestureRecognizer){
        if sender.state == .ended {
            print("UIGestureRecognizerStateEnded")

            recordingCounter.invalidate()

            seconds = 0
            minutes = 0

            if self.timerView.alpha == 1.0 {
            UIView.animate(withDuration: 0.2, animations: {

                self.timerView.alpha = 0.0
                self.timerView.isHidden = true
                self.recordingCounter.invalidate()

                self.seconds = 0
                self.minutes = 0

                self.counterString = "00:00"
                self.countingLabel.text = self.counterString
            })
            }

    return

        }else if sender.state == .began {

            timerView.isHidden = false
            UIView.animate(withDuration: 0.2, animations: {

                self.timerView.alpha = 1.0

            })

            print("UIGestureRecognizerStateBegan.")

            recordingCounter = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(updateCounter), userInfo: nil, repeats: true)
        }
    }

func updateCounter() {

        seconds += 1
        if seconds == 60 {

            minutes += 1
            seconds = 0

        }

        let secondsString = seconds > 9 ? "\(seconds)" : "0\(seconds)"
        let minutesString = minutes > 9 ? "\(minutes)" : "0\(minutes)"

        counterString = "\(minutesString):\(secondsString)"
        countingLabel.text = counterString

    }

顺便说一句，我同时运行我的自定义 AVFoundation 相机的 VideoPreviewLayer.. 可能会导致问题吗？

Answer 1

Timer 在与用户交互相同的 DispatchQueue 中工作(例如在 UITableView 中滚动，在 UIGestureRecognizer 或按住 UIbutton)。因此，当用户执行任何操作时，Timer 将卡住片刻。

您可以使用例如 AsyncTimer 来解决这个问题.