在app中为所有UIViewController的标题实现一个DidSet

import UIKit

extension UIViewController {
    override open var title: String? {
        didSet {
            // 在这里处理 title 变化的逻辑
            print("Title changed to \(title ?? "")")
            // 例如，更新导航栏标题
            navigationController?.navigationBar.topItem?.title = title
        }
    }
}

import UIKit

class BaseViewController: UIViewController {
    override open var title: String? {
        didSet {
            // 在这里处理 title 变化的逻辑
            print("Title changed to \(title ?? "")")
            // 例如，更新导航栏标题
            navigationController?.navigationBar.topItem?.title = title
        }
    }
}

class MyViewController: BaseViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        self.title = "My View Controller"
    }
}

extension Notification.Name {
    static let titleDidChange = Notification.Name("titleDidChange")
}

import UIKit

class MyViewController: UIViewController {
    override open var title: String? {
        didSet {
            NotificationCenter.default.post(name: .titleDidChange, object: self)
        }
    }
}

NotificationCenter.default.addObserver(self, selector: #selector(handleTitleDidChange), name: .titleDidChange, object: nil)

@objc func handleTitleDidChange(notification: Notification) {
    if let viewController = notification.object as? UIViewController {
        print("Title changed to \(viewController.title ?? "")")
    }
}

deinit {
    NotificationCenter.default.removeObserver(self, name: .titleDidChange, object: nil)
}