如何将UITextview设置为喜欢Rounded Rect文本字段？

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()

        let textView = UITextView(frame: CGRect(x: 20, y: 100, width: 280, height: 100))
        textView.text = "这是一个圆角矩形文本框"
        textView.backgroundColor = .white
        textView.layer.cornerRadius = 10.0
        textView.layer.borderWidth = 1.0
        textView.layer.borderColor = UIColor.gray.cgColor
        textView.font = UIFont.systemFont(ofSize: 16)

        self.view.addSubview(textView)
    }
}