ios - 不调用 UINavigationControllerDelegate 方法

Question

我正在尝试在从自定义 UINavigationController 类推送/弹出 viewController 时进行自定义转换。我正在实现 UINavigationControllerDelegate 方法navigationController(_:animationControllerFor:from:to:)，但它不会被调用。

我正在 Storyboard 中创建一个 UINavigationController 并将它的类作为 CustomNavigationController。我还在 Storyboard中为它分配了一个根 ViewController(我们称根 VC CustomViewControllerRoot)。

这是我正在使用的代码(经过简化且未经测试):

protocol NavigationDelegate {
 func pushCustomViewController()
 func popViewController()
}

class CustomNavigationController: UINavigationController, NavigationDelegate {

    init() {
      super.init(nibName: nil, bundle: nil)
      delegate = self
    }

    required init?(coder aDecoder: NSCoder) {
      super.init(coder: aDecoder)
    }

    override func viewDidLoad() {
      self.navigationBar.isHidden = true

      guard viewControllers.first is CustomViewControllerRoot else {fatalError("Error")}
      rootVC = viewControllers.first as? CustomViewControllerRoot
      rootVC?.navigationDelegate = self

      //Setup the rest of the viewControllers that are to be used
      customVC = CustomUIViewController()
      customVC?.navigationDelegate = self
    }

    var rootVC: CustomViewControllerRoot?
    var customVC: CustomViewController?    

    func pushCustomViewController() {
      if customVC != nil {
         self.pushViewController(customVC!, animated: true)
      }
    }

    func popViewController() {
      self.popViewController(animated: true)
    }
}


extension CustomNavigationController: UINavigationControllerDelegate {
    func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationController.Operation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        // This is never called, even though the delegate is set in the initializer to CustomNavigationController
        print("TEST")
        return nil
    }

}

然后我让我的导航层次结构中的每个自定义 UIViewController 子类委托(delegate)推送或弹出到上面的这个 CustomNavigationController。例如，这是分配给导航 Controller 的根 vc。因为它位于根目录下，所以它永远不需要推送自己或被弹出，因为它在 CustomNavigationController 出现时出现。当它发现另一个 VC 应该出现在它上面时，它委托(delegate)给 CustomNavigationController:

class CustomViewControllerRoot {

 var navigationDelegate: NavigationDelegate?

 override func viewDidLoad(){
   super.viewDidLoad()
 }

 @objc func someButtonPressedToPresentCustomVC(){
   navigationDelegate?.pushCustomViewController()
 }

}

解雇是在每个 CustomViewController 内部处理的，它还将弹出委托(delegate)给 CustomNavigationController(我不想使用导航栏来解雇，所以没有“后退按钮”从头开始):

class CustomViewController: UIViewController {

 var navigationDelegate: NavigationDelegate?

 override func viewDidLoad(){
   super.viewDidLoad()
 }

 @objc func dismissViewController(){
   navigationDelegate?.popViewController()
 }  
}

根据我的理解，CustomNavigationController 扩展中的 UINavigationControllerDelegate 方法应该在执行推送或弹出时被调用，因为我正在设置 delegate 变量到初始化程序中的 self？

Answer 1

您的导航 Controller 应该有一个 Root View Controller 。然后你应该从你的 Root View Controller 推送自定义 View Controller 。并委托(delegate)方法调用

导航 Controller 代码:import UIKit

class CustomNV: UINavigationController {
    override func viewDidLoad() {
        super.viewDidLoad()
        delegate = self
    }
}

extension CustomNV: UINavigationControllerDelegate {
    func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationController.Operation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        print("TEST")
        return nil
    }
}

RootViewController代码:

class RootViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        let viewController = UIViewController(nibName: nil, bundle: nil)
        viewController.view.backgroundColor = .green
        navigationController?.pushViewController(viewController, animated: true)
    }

}

将 Root View Controller 设置为 Storyboard中导航 Controller 的根