如何使用UITextView增加视图高度？

import UIKit

class ViewController: UIViewController, UITextViewDelegate {
    var textView: UITextView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建UITextView
        textView = UITextView(frame: CGRect(x: 20, y: 20, width: 200, height: 100))
        textView.delegate = self
        textView.font = UIFont.systemFont(ofSize: 16)
        textView.textColor = UIColor.black
        textView.textAlignment = .left
        textView.isScrollEnabled = false
        textView.layer.borderWidth = 1
        textView.layer.borderColor = UIColor.lightGray.cgColor
        textView.text = "这是一个UITextView示例"
        
        // 将UITextView添加到父视图
        self.view.addSubview(textView)
    }
    
    // UITextViewDelegate方法，当文本内容发生变化时调用
    func textViewDidChange(_ textView: UITextView) {
        // 获取内容大小
        let contentSize = textView.sizeThatFits(textView.bounds.size)
        
        // 更新UITextView的高度
        textView.frame.size.height = contentSize.height
        
        // 更新父视图或布局约束
        // ...
    }
}