根据contenView大小以编程方式调整scrollView大小[Swift]

import UIKit

class ViewController: UIViewController {
    var scrollView: UIScrollView!
    var contentView: UIView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建UIScrollView实例
        scrollView = UIScrollView(frame: CGRect(x: 0, y: 0, width: view.frame.width, height: view.frame.height))
        view.addSubview(scrollView)
        
        // 创建内容视图
        contentView = UIView(frame: CGRect(x: 0, y: 0, width: scrollView.frame.width, height: 0))
        scrollView.addSubview(contentView)
        
        // 添加内容到内容视图
        let label = UILabel(frame: CGRect(x: 0, y: 0, width: contentView.frame.width, height: 100))
        label.text = "这是一个示例文本"
        contentView.addSubview(label)
        
        // 调整内容视图大小
        contentView.frame.size.height = label.frame.maxY
        
        // 设置UIScrollView的contentSize为内容视图的大小
        scrollView.contentSize = contentView.frame.size
    }
}