Swift ios无法将动画设置为无限大

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建一个视图
        let myView = UIView(frame: CGRect(x: 100, y: 100, width: 100, height: 100))
        myView.backgroundColor = UIColor.red
        view.addSubview(myView)
        
        // 创建一个基本动画
        let animation = CABasicAnimation(keyPath: "position")
        animation.fromValue = NSValue(cgPoint: myView.center)
        animation.toValue = NSValue(cgPoint: CGPoint(x: 200, y: 200))
        animation.duration = 1.0
        animation.repeatCount = .infinity // 设置为无限大
        
        // 将动画添加到视图的图层上
        myView.layer.add(animation, forKey: "positionAnimation")
    }
}