从不调用交互式代理方法

Question

我想在ViewController(1)和NavigationViewController(2)之间进行交互式转换.

NavigationController由一个按钮调用,因此在呈现时没有交互式转换.它可以通过按钮或UIPanGestureRecognizer来解除,因此它可以被交互或不被解雇.

我有一个名为TransitionManager的对象,用于转换,UIPercentDrivenInteractiveTransition的子类.

下面的代码的问题interactionControllerFor...是永远不会调用两个委托方法.

此外,当我按下按钮或swip(UIPanGestureRecognizer)时,模态segue的基本动画完成.所以这两个委托方法animationControllerFor...也不起作用.

有任何想法吗 ？谢谢

ViewController.swift

let transitionManager = TransitionManager()

override func viewDidLoad() {
    super.viewDidLoad()

    self.transitioningDelegate = transitionManager
}

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {

        let dest = segue.destinationViewController as UIViewController
        dest.transitioningDelegate = transitionManager
        dest.modalPresentationStyle = .Custom
}

TransitionManager.swift

class TransitionPushManager: UIPercentDrivenInteractiveTransition,
 UINavigationControllerDelegate, UIViewControllerTransitioningDelegate {


@IBOutlet var navigationController: UINavigationController!

var animation : Animator! // Implement UIViewControllerAnimatedTransitioning protocol


override func awakeFromNib() {
    var panGesture = UIPanGestureRecognizer(target: self, action: "gestureHandler:")
    navigationController.view.addGestureRecognizer(panGesture)

    animation = Animator()
}

func gestureHandler(pan : UIPanGestureRecognizer) {

    switch pan.state {

    case .Began :

        interactive = true

            navigationController.presentingViewController?.dismissViewControllerAnimated(true, completion:nil)


    case .Changed :

        ...            

    default :

        ...

        interactive = false

    }

}


func animationControllerForPresentedController(presented: UIViewController, presentingController presenting: UIViewController, sourceController source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
    return animation
}

func animationControllerForDismissedController(dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
    return animation
}

func interactionControllerForPresentation(animator: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {
    return nil
}

func interactionControllerForDismissal(animator: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {
    return self.interactive ? self : nil
}

Main.storyboard

• ViewController上的按钮触发了一个模态segue来呈现NavigationController

• NavigationController的委托出口链接到TransitionManager类的对象

• NavigationController在属性"navigationController"的TransitionManager类中引用

Answer 1

我认为关键问题是你正在配置transitionDelegatein viewDidLoad.在这个过程中,这通常为时已晚.你应该像init导航控制器那样做.

让我们想象你的根场景("Root"),它呈现导航控制器场景("Nav"),然后从场景A推送到B到C,例如,我想象一个像这样的对象模型,导航控制器只会拥有自己的动画控制器,交互控制器和手势识别器:

这是您在考虑(a)"root"呈现"nav"时的自定义转换(非交互式)时所需要的; (b)当"nav"自行解散以返回"根"时的自定义转换(交互与否).所以,我将导航控制器子类化为:

• 在其视图中添加手势识别器;

• 设置在transitioningDelegate从根场景转换到导航控制器场景(并返回)时生成自定义动画:

• 的transitioningDelegate也将返回交互控制器(当手势识别正在进行将仅存在),产生手势和非交互式转换期间交互式过渡如果关闭该手势的上下文之外.

在Swift 3中,它看起来像:

import UIKit
import UIKit.UIGestureRecognizerSubclass

class CustomNavigationController: UINavigationController {

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

    override init(rootViewController: UIViewController) {
        super.init(rootViewController: rootViewController)
        configure()
    }

    private func configure() {
        transitioningDelegate = self   // for presenting the original navigation controller
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        delegate = self                // for navigation controller custom transitions

        let left = UIScreenEdgePanGestureRecognizer(target: self, action: #selector(handleSwipeFromLeft(_:)))
        left.edges = .left
        view.addGestureRecognizer(left)
    }

    fileprivate var interactionController: UIPercentDrivenInteractiveTransition?

    func handleSwipeFromLeft(_ gesture: UIScreenEdgePanGestureRecognizer) {
        let percent = gesture.translation(in: gesture.view!).x / gesture.view!.bounds.size.width

        if gesture.state == .began {
            interactionController = UIPercentDrivenInteractiveTransition()
            if viewControllers.count > 1 {
                popViewController(animated: true)
            } else {
                dismiss(animated: true)
            }
        } else if gesture.state == .changed {
            interactionController?.update(percent)
        } else if gesture.state == .ended {
            if percent > 0.5 && gesture.state != .cancelled {
                interactionController?.finish()
            } else {
                interactionController?.cancel()
            }
            interactionController = nil
        }
    }
}

// MARK: - UINavigationControllerDelegate
//
// Use this for custom transitions as you push/pop between the various child view controllers 
// of the navigation controller. If you don't need a custom animation there, you can comment this
// out.

extension CustomNavigationController: UINavigationControllerDelegate {

    func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationControllerOperation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {

        if operation == .push {
            return ForwardAnimator()
        } else if operation == .pop {
            return BackAnimator()
        }
        return nil
    }

    func navigationController(_ navigationController: UINavigationController, interactionControllerFor animationController: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {
        return interactionController
    }

}

// MARK: - UIViewControllerTransitioningDelegate
//
// This is needed for the animation when we initially present the navigation controller. 
// If you're only looking for custom animations as you push/pop between the child view
// controllers of the navigation controller, this is not needed. This is only for the 
// custom transition of the initial `present` and `dismiss` of the navigation controller 
// itself.

extension CustomNavigationController: UIViewControllerTransitioningDelegate {

    func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        return ForwardAnimator()
    }

    func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        return BackAnimator()
    }

    func interactionControllerForPresentation(using animator: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {
        return interactionController
    }

    func interactionControllerForDismissal(using animator: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {
        return interactionController
    }

    func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController? {
        return PresentationController(presentedViewController: presented, presenting: presenting)
    }

}

// When doing custom `present`/`dismiss` that overlays the entire
// screen, you generally want to remove the presenting view controller's
// view from the view hierarchy. This presentation controller
// subclass accomplishes that for us.

class PresentationController: UIPresentationController {
    override var shouldRemovePresentersView: Bool { return true }
}

// You can do whatever you want in the animation; I'm just fading

class ForwardAnimator : NSObject, UIViewControllerAnimatedTransitioning {

    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return 0.5
    }

    func animateTransition(using context: UIViewControllerContextTransitioning) {
        let toView = context.viewController(forKey: .to)!.view!

        context.containerView.addSubview(toView)

        toView.alpha = 0.0

        UIView.animate(withDuration: transitionDuration(using: context), animations: {
            toView.alpha = 1.0
        }, completion: { finished in
            context.completeTransition(!context.transitionWasCancelled)
        })
    }

}

class BackAnimator : NSObject, UIViewControllerAnimatedTransitioning {

    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return 0.5
    }

    func animateTransition(using context: UIViewControllerContextTransitioning) {
        let toView   = context.viewController(forKey: .to)!.view!
        let fromView = context.viewController(forKey: .from)!.view!

        context.containerView.insertSubview(toView, belowSubview: fromView)

        UIView.animate(withDuration: transitionDuration(using: context), animations: {
            fromView.alpha = 0.0
        }, completion: { finished in
            context.completeTransition(!context.transitionWasCancelled)
        })
    }
}

所以,我可以将故事板中导航控制器的基类更改为此自定义子类,现在根场景可以只显示导航控制器(没有特殊功能prepare(for:)),一切正常.