如何在 UIStoryboardSegue 中实现 UIViewControllerTransitioningDelegate？

Question

这就是我现在所做的：

func presentOverlayController(controller: UIViewController) {

    controller.modalPresentationStyle = .Custom
    controller.transitioningDelegate = self

    presentViewController(controller, animated: true, completion: nil)
}

//MARK: - UIViewControllerTransitioningDelegate

public func presentationControllerForPresentedViewController(presented: UIViewController, presentingViewController presenting: UIViewController, sourceViewController source: UIViewController) -> UIPresentationController? {
    return OverlayPresentationController(presentedViewController: presented, presentingViewController: presenting)
}

效果非常棒。首先，我使用 .instantiateViewControllerWithIdentifier: 从情节提要中获取控制器。控制器的正确呈现方式：

但是我需要用我的自定义 segue:

实现相同的结果

class OverlaySegue: UIStoryboardSegue, UIViewControllerTransitioningDelegate {

    override func perform() {

        destinationViewController.modalPresentationStyle = .Custom
        destinationViewController.transitioningDelegate = self
    }

    //MARK: - UIViewControllerTransitioningDelegate

    func presentationControllerForPresentedViewController(presented: UIViewController, presentingViewController presenting: UIViewController, sourceViewController source: UIViewController) -> UIPresentationController? {
        return OverlayPresentationController(presentedViewController: presented, presentingViewController: presenting)
    }
}

但它不起作用。为什么？

Answer 1

在 perform 结束时，您需要调用 presentViewController(destinationViewController, animated: true, completion: nil)。