iPhone 的高分辨率计时器

iPhone 的高分辨率计时器

swift
import UIKit
class TimerViewController: UIViewController {
    var timer: Timer?
    var startTime: TimeInterval = 0
    
    @IBOutlet weak var timeLabel: UILabel!
    
    override func viewDidLoad() {
        super.viewDidLoad()
    }
    
    @IBAction func startTimer(_ sender: UIButton) {
        startTime = Date().timeIntervalSinceReferenceDate
        timer = Timer.scheduledTimer(timeInterval: 0.01, target: self, selector: #selector(updateTimer), userInfo: nil, repeats: true)
    }
    
    @IBAction func stopTimer(_ sender: UIButton) {
        timer?.invalidate()
        timer = nil
    }
    
    @objc func updateTimer() {
        let currentTime = Date().timeIntervalSinceReferenceDate - startTime
        let minutes = Int(currentTime / 60)
        let seconds = Int(currentTime) % 60
        let milliseconds = Int((currentTime * 100).truncatingRemainder(dividingBy: 100))
        
        timeLabel.text = String(format: "%02d:%02d:%02d", minutes, seconds, milliseconds)
    }
}