如何在Swift中使用deltaTime正确计算1秒

import UIKit

class ViewController: UIViewController {
    var displayLink: CADisplayLink?
    var startTime: CFTimeInterval = 0.0
    var accumulatedTime: CFTimeInterval = 0.0
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        displayLink = CADisplayLink(target: self, selector: #selector(update))
        displayLink?.add(to: .main, forMode: .default)
        startTime = CACurrentMediaTime()
    }
    
    @objc func update() {
        let currentTime = CACurrentMediaTime()
        let deltaTime = currentTime - startTime
        startTime = currentTime
        
        accumulatedTime += deltaTime
        
        if accumulatedTime >= 1.0 {
            // 执行1秒后的操作
            print("1秒已过")
            accumulatedTime = 0.0
        }
    }
}