iphone - 如何控制CALayer的影子呢？

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建一个视图
        let view = UIView(frame: CGRect(x: 100, y: 100, width: 200, height: 200))
        view.backgroundColor = UIColor.white
        
        // 创建一个CALayer对象
        let shadowLayer = CALayer()
        shadowLayer.frame = view.bounds
        
        // 设置阴影属性
        shadowLayer.shadowColor = UIColor.black.cgColor
        shadowLayer.shadowOffset = CGSize(width: 0, height: 3)
        shadowLayer.shadowOpacity = 0.5
        shadowLayer.shadowRadius = 5
        
        // 设置阴影的形状
        let shadowPath = UIBezierPath(rect: view.bounds)
        shadowLayer.shadowPath = shadowPath.cgPath
        
        // 将CALayer添加到视图的layer中
        view.layer.addSublayer(shadowLayer)
        
        // 将视图添加到当前视图控制器的view中
        self.view.addSubview(view)
    }
}