UINavigationControllerDelegate 不起作用

Posted 2023-03-22

【中文标题】UINavigationControllerDelegate 不起作用

【英文标题】：UINavigationControllerDelegate doesn't work

【发布时间】：2015-10-27 04:03:32

【问题描述】：

更新到正确的版本，既然得到了答案。

我想在导航视图控制器弹出/push时做淡入/淡出动画，然后我实现BaseViewController：

class BaseViewController: UIViewController, UINavigationControllerDelegate 

    override func viewWillAppear(animated: Bool) 
        super.viewWillAppear(animated)
        self.navigationController?.delegate = self
    


    func navigationController(navigationController: UINavigationController, animationControllerForOperation operation: UINavigationControllerOperation, fromViewController fromVC: UIViewController, toViewController toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? 

        if (operation == UINavigationControllerOperation.Push) 
            return FadeInAnimator()
        

        if (operation == UINavigationControllerOperation.Pop) 
            return FadeOutAnimator()
        
        return nil;
    

和FadeInAnimator、FadeOutAnimator：

class FadeInAnimator: NSObject, UIViewControllerAnimatedTransitioning 

    func transitionDuration(transitionContext: UIViewControllerContextTransitioning?) -> NSTimeInterval 
        return 0.5
    

    func animateTransition(transitionContext: UIViewControllerContextTransitioning) 

        let toViewController = transitionContext.viewControllerForKey(UITransitionContextToViewControllerKey)
        transitionContext.containerView()?.addSubview(toViewController!.view)
        toViewController?.view.alpha = 0.0
        UIView.animateWithDuration(self.transitionDuration(transitionContext), animations:  () -> Void in
            toViewController?.view.alpha = 1.0
        )  (finished) -> Void in
            transitionContext.completeTransition(!transitionContext.transitionWasCancelled())
        
    


class FadeOutAnimator: NSObject, UIViewControllerAnimatedTransitioning 
    func transitionDuration(transitionContext: UIViewControllerContextTransitioning?) -> NSTimeInterval 
        return 0.5
    

    func animateTransition(transitionContext: UIViewControllerContextTransitioning) 
        let toViewController = transitionContext.viewControllerForKey(UITransitionContextToViewControllerKey)
        let fromViewController = transitionContext.viewControllerForKey(UITransitionContextFromViewControllerKey)
        transitionContext.containerView()?.insertSubview((toViewController?.view)!, belowSubview: (fromViewController?.view)!)

        UIView.animateWithDuration(self.transitionDuration(transitionContext), animations:  () -> Void in
            fromViewController?.view.alpha = 0.0
        )  (finished) -> Void in
            transitionContext.completeTransition(!transitionContext.transitionWasCancelled())
    

然后，我添加 2 个视图控制器并嵌入导航视图控制器，ViewControllerA 和 ViewControllerB：

class ViewControllerA: BaseViewController 

    override func viewDidLoad() 
        super.viewDidLoad()
    

    @IBAction func pressButton(sender: UIButton) 

        if let vc = create(ViewControllerB) 
            self.navigationController?.pushViewController(vc, animated: true)
        
      


class ViewControllerB: BaseViewController 

    override func viewDidLoad() 
        super.viewDidLoad()

    

按ViewControllerA 上的按钮将创建并跳转到ViewControllerB，然后按ViewControllerB 上的导航栏项目“返回”将返回到ViewControllerA。

但它不起作用，当按下按钮时，ViewControllerA 显示ViewControllerB，然后再次显示ViewControllerA。

有什么建议吗？我的 xcode 是 7.1，在 iPad Air 2 模拟器上运行。

【参考方案1】：

在动画完成块的 FadeInAnimator 中

改一下

transitionContext.completeTransition(transitionContext.transitionWasCancelled())

到

transitionContext.completeTransition(!transitionContext.transitionWasCancelled())

【讨论】：

更改为 follow 后，现在可以正常工作：transitionContext.completeTransition(!transitionContext.transitionWasCancelled())