ios - 增加 dismissViewControllerAnimated() 的持续时间

Question

我一直在尝试找出如何增加 dismissViewControllerAnimated(true, completion: nil) 的持续时间，但似乎无法在 Apples documentation 中找到答案.我的 View Controller 从下到上显示动画，并在关闭时以相反的顺序运行。我想让动画慢一点，比如 0.5 秒，有什么建议吗？

Answer 1

您必须为 View Controller 使用自定义转换。请看一下这个精彩的教程来帮助您入门:http://www.appcoda.com/custom-view-controller-transitions-tutorial/

在此处添加主要代码，以防将来链接被删除:

创建一个名为 CustomPresentAnimationController 的新类，并使其成为 NSObject 的子类。 类 CustomPresentAnimationController: NSObject, UIViewControllerAnimatedTransitioning

UIViewControllerAnimatedTransitioning 协议(protocol)有两个必需的方法，我们接下来将添加它们。将以下方法添加到类中。

    func transitionDuration(transitionContext: UIViewControllerContextTransitioning) -> NSTimeInterval {
        return 2.5
    }

    func animateTransition(transitionContext: UIViewControllerContextTransitioning) {

    let fromViewController = transitionContext.viewControllerForKey(UITransitionContextFromViewControllerKey)!
    let toViewController = transitionContext.viewControllerForKey(UITransitionContextToViewControllerKey)!
    let finalFrameForVC = transitionContext.finalFrameForViewController(toViewController)
    let containerView = transitionContext.containerView()
    let bounds = UIScreen.mainScreen().bounds
    toViewController.view.frame = CGRectOffset(finalFrameForVC, 0, bounds.size.height)
    containerView.addSubview(toViewController.view)

    UIView.animateWithDuration(transitionDuration(transitionContext), delay: 0.0, usingSpringWithDamping: 0.5, initialSpringVelocity: 0.0, options: .CurveLinear, animations: {
        fromViewController.view.alpha = 0.5
        toViewController.view.frame = finalFrameForVC
        }, completion: {
            finished in
            transitionContext.completeTransition(true)
            fromViewController.view.alpha = 1.0
    })}

动画 Controller 完成后，我们需要将其链接到 Storyboard转场。 打开 ItemsTableViewController.swift 文件并更改类声明，如下所示。

class ItemsTableViewController: UITableViewController, UIViewControllerTransitioningDelegate {

将其添加到此类中以处理转场:

let customPresentAnimationController = CustomPresentAnimationController()

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

    if segue.identifier == "showAction" {
        let toViewController = segue.destinationViewController as UIViewController
        toViewController.transitioningDelegate = self
    }
}

将以下UIViewControllerTransitioningDelegate方法添加到类中。这将返回我们的自定义动画 Controller 的实例。

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

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