如何在Swift 5中将UIView设置为半圆

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let view = UIView(frame: CGRect(x: 100, y: 100, width: 100, height: 100))
        view.backgroundColor = UIColor.red
        
        // 设置圆角
        view.layer.cornerRadius = view.frame.width / 2
        view.clipsToBounds = true
        
        self.view.addSubview(view)
    }
}