使用一个UIViewController和两个XIB在iPad上处理方向更改

import UIKit

class MyViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // 注册设备方向变化通知
        NotificationCenter.default.addObserver(self, selector: #selector(deviceOrientationDidChange), name: UIDevice.orientationDidChangeNotification, object: nil)

        // 加载适当的XIB文件
        loadXib()
    }

    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
        super.viewWillTransition(to: size, with: coordinator)

        // 处理方向变化
        coordinator.animate(alongsideTransition: { _ in
            self.loadXib()
        }, completion: nil)
    }

    @objc func deviceOrientationDidChange() {
        // 更新视图
        loadXib()
    }

    func loadXib() {
        let deviceOrientation = UIDevice.current.orientation
        var xibName = ""

        switch deviceOrientation {
        case .portrait, .portraitUpsideDown:
            xibName = "MyViewControllerPortrait"
        case .landscapeLeft, .landscapeRight:
            xibName = "MyViewControllerLandscape"
        default:
            break
        }

        let nib = UINib(nibName: xibName, bundle: nil)
        let view = nib.instantiate(withOwner: self, options: nil).first as! UIView
        self.view = view
    }
}