ios - 黑屏出现在呈现的 View Controller 下方

Question

我正在尝试以模态方式呈现 View Controller 。它就像一个弹出 View Controller 。

我正在使用 animateTransition 方法为过渡设置动画。这是我的代码:

extension PopUpViewController: UIViewControllerTransitioningDelegate, UIViewControllerAnimatedTransitioning {

    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return 0.25
    }

    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {

        guard let fromVC = transitionContext.viewController(forKey: .from) else { return}
        guard let toVC = transitionContext.viewController(forKey: .to) else { return}
        guard let fromView = transitionContext.view(forKey: .from) else { return}
        guard let toView = transitionContext.view(forKey: .to) else { return}

        var containerView = transitionContext.containerView

        if toVC == self {
            // presenting
            containerView.addSubview(toView)
            toView.frame = fromView.frame
            popUpView.transform = CGAffineTransform(scaleX: 0.5, y: 0.5)
            toView.alpha = 0
            UIView.animate(withDuration: 0.25, animations: {
                toView.alpha = 1
                self.popUpView.transform = CGAffineTransform.identity
            }) { _ in

                DispatchQueue.main.async {
                    transitionContext.completeTransition(true)
                }
            }
        } else {
            // dismissing
            UIView.animate(withDuration: 0.25, animations: {
                self.popUpView.transform = CGAffineTransform(scaleX: 0.5, y: 0.5)
                fromView.alpha = 0
            }) { _ in
                transitionContext.completeTransition(true)
            }
        }
    }

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

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

我以这种方式在另一个 View Controller (Presenting VC)上呈现这个 View Controller (Presented VC)。我正在使用默认的模态呈现样式。最初我使用的是自定义，但我查看了 StackOverflow 上的一些帖子，他们说要删除它，但我仍然遇到黑屏(显示 VC)并且我可以在上面看到显示的 VC。

当我关闭呈现的 VC 时，呈现的 VC 再次可见。

如果您需要更多详细信息，请告诉我。

根据transitionContext.completeTransition(true)执行时的代码，呈现VC屏幕变黑

Answer 1

您可以尝试将弹出 View Controller 的 modalPresentationStyle 设置为 .overCurrentContext 或 .overFullScreen。

case overCurrentContext:

A presentation style where the content is displayed over another view controller’s content.

这意味着它将在 viewController 的内容上显示下一个 viewController。

所以对于 Container ViewControllers:

因此，如果您有任何 tabBarController，tabBar 将允许用户与之交互。

case overFullScreen

A view presentation style in which the presented view covers the screen.

这意味着它将在全屏上呈现下一个 viewController，因此 taBar 在呈现完成之前不会交互。

func presentNextController() {
    // In case your viewController is in storyboard or any other initialisation
    guard let nextVC = storyboard.instantiateViewController(with: "nextVC") as? NextViewController else { return }

    nextVC.modalPresentationStyle = .overFullScreen
    // set your custom transitioning delegate

    self.present(nextVC, animated: true, completion: nil)
}