swift - 为什么我的自定义转换不适用于我的导航 Controller ？

Question

我在代码中使用协调器模式从 RootNavigationController 转换到 SplashScreenViewController

class AppCoordinator {
    let window: UIWindow
    let rootViewController: RootNavigationController

    init(window: UIWindow) {
        self.window = window
        rootViewController = RootNavigationController()
        let splashScreenViewController = SplashScreenViewController()

rootViewController.pushViewController(splashScreenViewController, animated: false)
    }
}
extension AppCoordinator: Coordinator {
    func start() {
        window.rootViewController = rootViewController
        window.makeKeyAndVisible()
    }
}

我还使用自定义转换来处理从 RootNavigationController 到 SplashScreenNavigationController 的转换。

class FadeInAnimator: NSObject {
var duration: TimeInterval = 1.0
}
extension FadeInAnimator: UIViewControllerAnimatedTransitioning {
    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
    return duration
}

func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
    let containerView = transitionContext.containerView

guard let toViewController = transitionContext.viewController(forKey: .to) else { return }

containerView.addSubview(toViewController.view)
    toViewController.view.alpha = 0

let durationOfTransition = transitionDuration(using: transitionContext)
    UIView.animate(withDuration: durationOfTransition, delay: 0, options: [.curveEaseIn], animations: {
        toViewController.view.alpha = 1
    }) { (finished) in
        transitionContext.completeTransition(finished)
        }
    }
}

我已将 RootNavigationController 的委托(delegate)设置为其自身并实现了动画转换，但是，当我启动应用程序时，它似乎忽略了我所做的一切，仅使用系统默认转换。

这是 RootNavigationController 中的代码

class RootNavigationController: UINavigationController {
override func viewDidLoad() {
    super.viewDidLoad()
    delegate = self
    navigationBar.setBackgroundImage(UIImage(), for: .default)
    navigationBar.shadowImage = UIImage()
}
override var preferredStatusBarStyle: UIStatusBarStyle {
    return .lightContent
}
}
extension RootNavigationController: UINavigationControllerDelegate {
func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationControllerOperation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
    switch operation {
    case .push: return FadeInAnimator()
    case .pop: return nil
    case .none: return nil
    }
}
}

Answer 1

删除打开和关闭括号

UIView.animate(withDuration: durationOfTransition, delay: 0, options: .curveEaseIn, animations: