从XIB添加的Swift滚动视图根本不能滚动

import UIKit

class ViewController: UIViewController {
    @IBOutlet weak var scrollView: UIScrollView!
    @IBOutlet weak var contentView: UIView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 设置内容视图的大小，确保大于滚动视图的大小
        contentView.frame = CGRect(x: 0, y: 0, width: scrollView.frame.width, height: scrollView.frame.height)
        
        // 设置滚动视图的内容大小
        scrollView.contentSize = contentView.frame.size
        
        // 启用滚动功能
        scrollView.isScrollEnabled = true
    }
}