不使用 Storyboard segues 的自定义视图转换 (Swift)

Posted 2023-03-14

【中文标题】不使用 Storyboard segues 的自定义视图转换 (Swift)

【英文标题】：Custom View Transition without use of Storyboard segues (Swift)

【发布时间】：2015-07-27 00:02:36

【问题描述】：

我有两个视图，我想做一个滑动样式的过渡，当有一个 segue 可以操作时我已经这样做了，但是我这里没有一个，所以我不确定如何应用我的动画类。我在课堂上只有：

let stb = UIStoryboard(name: "Walkthrough", bundle: nil)
    let walkthrough = stb.instantiateViewControllerWithIdentifier("walk") as! BWWalkthroughViewController

self.presentViewController(walkthrough, animated: true, completion: nil)

我想申请应用以下自定义segue：

class CustomSegue: UIStoryboardSegue 

  override func perform() 
    // Assign the source and destination views to local variables.
    var firstVCView = self.sourceViewController.view as UIView!
    var secondVCView = self.destinationViewController.view as UIView!

    // Get the screen width and height.
    let screenWidth = UIScreen.mainScreen().bounds.size.width
    let screenHeight = UIScreen.mainScreen().bounds.size.height

    // Specify the initial position of the destination view.
    secondVCView.frame = CGRectMake(0.0, screenHeight, screenWidth, screenHeight)

    // Access the app's key window and insert the destination view above the current (source) one.
    let window = UIApplication.sharedApplication().keyWindow
    window?.insertSubview(secondVCView, aboveSubview: firstVCView)

    // Animate the transition.
    UIView.animateWithDuration(0.2, animations:  () -> Void in
      firstVCView.frame = CGRectOffset(firstVCView.frame, -screenWidth, 0.0)
      secondVCView.frame = CGRectOffset(secondVCView.frame, -screenWidth, 0.0)

      )  (Finished) -> Void in

      self.sourceViewController.presentViewController(self.destinationViewController as! UIViewController,
          animated: false,
          completion:nil)
    
  

我不能让它工作请任何指针？

【问题讨论】：

请注意，您不需要使用UIScreen.mainScreen()，它实际上可能会造成一些混乱。另请注意，如果您将动画减慢到 4 秒，它似乎会显示不受欢迎的伪影。

【参考方案1】：

虽然第一个答案应该是“使用 Storyboard Segues”，但您可以通过这种方式解决自定义转换：

通用方法

修改您的 CustomSegue 以采用 both UIStoryboardSegue 和 UIViewControllerAnimatedTransitioning 协议。 重构 CustomSegue 以便两个协议都可以使用动画。 为导航控制器设置一个delegate，它可以是它自己，以提供自定义转换到push和pop 让animationControllerForOperation 创建并返回CustomSegue 的实例，并带有您选择的标识符。

概述

// Adopt both protocols
class CustomSegue: UIStoryboardSegue, UIViewControllerAnimatedTransitioning 

    func animate(firstVCView:UIView,
        secondVCView:UIView,
        containerView:UIView,
        transitionContext: UIViewControllerContextTransitioning?) 
            // factored transition code goes here
                )  (Finished) -> Void in
                    if let context = transitionContext 
                        // UIViewControllerAnimatedTransitioning
                     else 
                        // UIStoryboardSegue
                    
            
    

    func transitionDuration(transitionContext: UIViewControllerContextTransitioning) -> NSTimeInterval 
        // return timing
    

    func animateTransition(transitionContext: UIViewControllerContextTransitioning) 
        // Perform animate using transitionContext information
        // (UIViewControllerAnimatedTransitioning)
    

    override func perform() 
        // Perform animate using segue (self) variables
        // (UIStoryboardSegue) 
    

---

以下是完整代码示例。它已经过测试。请注意，我还修复了原始问题中的一些动画错误，并添加了淡入效果来强调动画。

---

CustomSegue 类

// Animation for both a Segue and a Transition
class CustomSegue: UIStoryboardSegue, UIViewControllerAnimatedTransitioning 

    func animate(firstVCView:UIView,
        secondVCView:UIView,
        containerView:UIView,
        transitionContext: UIViewControllerContextTransitioning?) 

            // Get the screen width and height.
            let offset = secondVCView.bounds.width

            // Specify the initial position of the destination view.
            secondVCView.frame = CGRectOffset(secondVCView.frame, offset, 0.0)

            firstVCView.superview!.addSubview(secondVCView)
            secondVCView.alpha = 0;

            // Animate the transition.
            UIView.animateWithDuration(self.transitionDuration(transitionContext!),
                animations:  () -> Void in
                    firstVCView.frame = CGRectOffset(firstVCView.frame, -offset, 0.0)
                    secondVCView.frame = CGRectOffset(secondVCView.frame, -offset, 0.0)
                    secondVCView.alpha = 1; // emphasis

                )  (Finished) -> Void in
                    if let context = transitionContext 
                        context.completeTransition(!context.transitionWasCancelled())
                     else 
                        self.sourceViewController.presentViewController(
                            self.destinationViewController as! UIViewController,
                            animated: false,
                            completion:nil)
                    
            
    

    func transitionDuration(transitionContext: UIViewControllerContextTransitioning) -> NSTimeInterval 
        return 4 // four seconds
    

    // Perform Transition (UIViewControllerAnimatedTransitioning)
    func animateTransition(transitionContext: UIViewControllerContextTransitioning) 
        self.animate(transitionContext.viewControllerForKey(UITransitionContextFromViewControllerKey)!.view,
            secondVCView: transitionContext.viewControllerForKey(UITransitionContextToViewControllerKey)!.view,
            containerView: transitionContext.containerView(),
            transitionContext: transitionContext)
    

    // Perform Segue (UIStoryboardSegue)
    override func perform() 
        self.animate(self.sourceViewController.view!!,
            secondVCView: self.destinationViewController.view!!,
            containerView: self.sourceViewController.view!!.superview!,
            transitionContext:nil)
    

宿主 ViewController 类

class ViewController: UIViewController, UINavigationControllerDelegate 

    override func viewDidLoad() 
        super.viewDidLoad()
        self.navigationController?.delegate = self
    

    func navigationController(navigationController: UINavigationController, animationControllerForOperation operation: UINavigationControllerOperation, fromViewController fromVC: UIViewController, toViewController toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? 
        switch operation 
        case .Push:
             return CustomSegue(identifier: "Abc", source: fromVC, destination: toVC)

        default:
            return nil
        
    

【讨论】：

谢谢，我看不到如何将它应用到我的代码中？

太棒了，我想在家里应用它。今晚下班后我会去，太棒了！

我应用了您的代码，但无法为宽度和高度属性设置动画。你知道这是为什么吗？

试过了，transitionContext不能为nil。作为transitionDuration（使用：transitionContext！）隐含不是零“transitionContext！”。