在 iPhone 或 iPad 上遍历视图层次结构

import UIKit

class ViewController: UIViewController {
    
    var view: UIView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 创建 UIView，并添加到 ViewController 中
        view = UIView(frame: CGRect(x: 0, y: 0, width: 320, height: 568))
        view.backgroundColor = .white
        
        // 获取当前视图控制器的所有视图控制器
        let viewControllers: [UIViewController] = self.viewControllers
        
        // 遍历所有视图控制器，获取它们的视图，并将视图添加到 UIView 中
        for viewController in viewControllers {
            if let view = viewController.view {
                view.frame = viewController.view.frame
                view.tag = viewController.restorationIdentifier!
                view.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleTap(recognizer:))))
                view.isUserInteractionEnabled = true
                view.tag = viewController.restorationIdentifier!
                viewControllers.remove(viewController)
                viewController.view = nil
            }
        }
        
        // 遍历视图层次结构，将所有视图的名称和标签添加到 UIView 中
        view.subviews.forEach { view in
            let label = UILabel()
            label.text = view.description
            label.frame = view.bounds
            view.addSubview(label)
        }
        
        // 在 iPhone 或 iPad 上显示视图层次结构
        view.frame = view.bounds
        view.autoresizingMask = [.flexibleTopMargin, .flexibleBottomMargin, .flexibleLeftMargin, .flexibleRightMargin]
        view.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handleTap(recognizer:))))
        view.isUserInteractionEnabled = true
    }
    
    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        
        // 在 iPhone 或 iPad 上更新视图层次结构
        let width = self.view.frame.width
        let height = self.view.frame.height
        let x = (width - height) / 2
        let y = (height - width) / 2
        view.frame = CGRect(x: x, y: y, width: width, height: height)
    }
    
    @objc func handleTap(recognizer: UITapGestureRecognizer) {
        // Handle the tap...
    }
}