如何在Swift中设置UILabel文本周围的阴影轮廓(实线)？

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建UILabel对象
        let label = UILabel(frame: CGRect(x: 50, y: 50, width: 200, height: 100))
        label.text = "Hello World"
        
        // 设置阴影属性
        label.layer.shadowColor = UIColor.black.cgColor
        label.layer.shadowOffset = CGSize(width: 2, height: 2)
        label.layer.shadowOpacity = 0.5
        label.layer.shadowRadius = 2
        
        // 设置边框属性
        label.layer.borderColor = UIColor.black.cgColor
        label.layer.borderWidth = 1
        label.layer.cornerRadius = 5
        
        // 将UILabel添加到视图中
        self.view.addSubview(label)
    }
}