如何在iOS上检测并停止滑动触发的返回导航？

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 添加自定义手势识别器
        let panGesture = UIPanGestureRecognizer(target: self, action: #selector(handlePan(_:)))
        navigationController?.view.addGestureRecognizer(panGesture)
    }
    
    @objc func handlePan(_ gestureRecognizer: UIPanGestureRecognizer) {
        // 获取手势的方向
        let velocity = gestureRecognizer.velocity(in: navigationController?.view)
        
        // 如果手势是向左滑动，并且当前视图控制器不是根视图控制器
        if velocity.x < 0 && navigationController?.viewControllers.count > 1 {
            // 阻止默认的返回行为
            gestureRecognizer.isEnabled = false
            gestureRecognizer.isEnabled = true // 重新启用，以便下次手势可以被检测
        }
    }
}