自定义 segue 过渡动画

Question

我正在开发一个使用导航控制器的应用程序。我有一个特定的视图控制器，在导航栏中有一个左右按钮，每个按钮都连接到不同的视图控制器。当我按下右键时，我只调用self.performSegue(withIdentifier: "ToDestination", sender: nil)，当我弹回来时，我调用_ = self.navigationController?.popViewController(animated: true)。

我的问题是当我按下左键时。我可以按下和弹出，但我希望过渡与右侧按钮相反。由于我按下左键，我希望 segue 从左到右转换，当我弹出时，我希望 segue 从右到左转换。

我可以通过以下方式让转换按照我想要的方式工作：

//push
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc = storyboard.instantiateViewController(withIdentifier: "SearchController") as! SearchController
let transition: CATransition = CATransition()
let timeFunc : CAMediaTimingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
transition.duration = 0.5
transition.timingFunction = timeFunc
transition.type = kCATransitionPush
transition.subtype = kCATransitionFromLeft
self.navigationController!.view.layer.add(transition, forKey: kCATransition)
self.navigationController!.pushViewController(vc, animated: true)

//pop
let transition: CATransition = CATransition()
let timeFunc : CAMediaTimingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionEaseInEaseOut)
transition.duration = 0.5
transition.timingFunction = timeFunc
transition.type = kCATransitionPush
transition.subtype = kCATransitionFromRight
self.navigationController!.view.layer.add(transition, forKey: kCATransition)
_ = self.navigationController?.popViewController(animated: true)

这可行，但是在视图控制器之间转换时会出现黑色闪烁。有没有更好的方法来获取默认的过渡动画？

Answer 1

实现这一点的最佳方法是通过遵循UIViewControllerAnimatedTransitioning 协议来创建自定义推送和弹出动画：-

//CustomPushAnimation class

import UIKit

class CustomPushAnimation: NSObject, UIViewControllerAnimatedTransitioning {

    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return 0.2
    }

    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        let containerVw = transitionContext.containerView
        let fromViewController = transitionContext.viewController(forKey: .from)
        let toViewController = transitionContext.viewController(forKey: .to)
        guard let fromVc = fromViewController, let toVc = toViewController else { return }
        let finalFrame = transitionContext.finalFrame(for: toVc)
        //Below line will start from left
        toVc.view.frame = finalFrame.offsetBy(dx: -finalFrame.size.width/2, dy: 0)
        containerVw.addSubview(toVc.view)
        UIView.animate(withDuration: transitionDuration(using: transitionContext), animations: {
            toVc.view.frame = finalFrame
            fromVc.view.alpha = 0.5
        }, completion: {(finished) in
            transitionContext.completeTransition(finished)
            fromVc.view.alpha = 1.0
        })
    }
}



//CustomPopAnimation class
import UIKit

class CustomPopAnimation: NSObject, UIViewControllerAnimatedTransitioning {
    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return 0.2
    }

    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        let containerView = transitionContext.containerView
        let fromViewController = transitionContext.viewController(forKey: .from)
        let toViewController = transitionContext.viewController(forKey: .to)
        guard let fromVc = fromViewController,
            let toVc = toViewController,
            let snapshotView = fromVc.view.snapshotView(afterScreenUpdates: false)
            else { return }
        let finalFrame = transitionContext.finalFrame(for: fromVc)
        toVc.view.frame = finalFrame
        containerView.addSubview(toVc.view)
        containerView.sendSubview(toBack: toVc.view)
        snapshotView.frame = fromVc.view.frame
        containerView.addSubview(snapshotView)
        fromVc.view.removeFromSuperview()
        UIView.animate(withDuration: transitionDuration(using: transitionContext), animations: {
            //Below line will start from right
            snapshotView.frame = finalFrame.offsetBy(dx: -finalFrame.size.width, dy: 0)
        }, completion: {(finished) in
            snapshotView.removeFromSuperview()
            transitionContext.completeTransition(finished)
        })
    }
}

最后你需要向新的 View 控制器展示设置 动画标志为真，否则将无法正常工作

//Below code should be inside YourViewController
    let vc = UIStoryboard(name: "storyboardName", bundle: nil).instantiateViewController(withIdentifier: "ViewControllerIdentifier")            let navigationController = BaseNavigationController(rootViewController: vc)
    navigationController.transitioningDelegate = self
    present(navigationController, animated: true, completion: nil)

你还需要符合 UIViewControllerTransitioningDelegate 协议以工作动画

  extension YourViewController: UIViewControllerTransitioningDelegate {
    func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
            return customPushAnimation
        }

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