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我有一个UICollectionView在3D Touch编辑时显示“Peek” 。作为默认行为，“Peek”会忽略导航栏。

但是，我确实想显示一个栏，就像下面显示的iMessage Peek一样：

在此处输入图像描述

Collection View Controller 和 Peek View Controller 都在 Navigation View Controller 中。

我在下面的 Apple 示例代码中有以下片段，我正在尝试根据上述需求进行修改：

extension ChatTableViewController: UIViewControllerPreviewingDelegate {
    func previewingContext(_ previewingContext: UIViewControllerPreviewing, viewControllerForLocation location: CGPoint) -> UIViewController? {
        guard let indexPath = tableView.indexPathForRow(at: location) else { return nil }

        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        let viewController = storyboard.instantiateViewController(withIdentifier: ChatDetailViewController.identifier)
        guard let chatDetailViewController = viewController as? ChatDetailViewController else { return nil }

        chatDetailViewController.chatItem = chatItem(at: indexPath)
        let cellRect = tableView.rectForRow(at: indexPath)
        previewingContext.sourceRect = previewingContext.sourceView.convert(cellRect, from: tableView)
        chatDetailViewController.isReplyButtonHidden = true

        return chatDetailViewController
    }

    func previewingContext(_ previewingContext: UIViewControllerPreviewing, commit viewControllerToCommit: UIViewController) {
        if let chatDetailViewController = viewControllerToCommit as? ChatDetailViewController {
            chatDetailViewController.isReplyButtonHidden = false
        }
        show(viewControllerToCommit, sender: self)
    }

更新

多亏了Leo Natan，我才能完成上述工作：

extension ChatTableViewController: UIViewControllerPreviewingDelegate {
    func previewingContext(_ previewingContext: UIViewControllerPreviewing, viewControllerForLocation location: CGPoint) -> UIViewController? {
        guard let indexPath = tableView.indexPathForRow(at: location) else { return nil }

        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        let viewController = storyboard.instantiateViewController(withIdentifier: ChatDetailViewController.identifier)
        guard let chatDetailViewController = viewController as? ChatDetailViewController else { return nil }

        chatDetailViewController.chatItem = chatItem(at: indexPath)
        let cellRect = tableView.rectForRow(at: indexPath)
        previewingContext.sourceRect = previewingContext.sourceView.convert(cellRect, from: tableView)
        chatDetailViewController.isReplyButtonHidden = true

        let navigationController = UINavigationController(rootViewController: viewController
        return navigationController
    }

    func previewingContext(_ previewingContext: UIViewControllerPreviewing, commit viewControllerToCommit: UIViewController) {
        if let chatDetailViewController = viewControllerToCommit as? ChatDetailViewController {
            chatDetailViewController.isReplyButtonHidden = false
        }
        show(viewControllerToCommit, sender: self)
    }

但是，这会创建一个新的导航控制器。如果我想最终使用相同的导航控制器，我可以这样做：

func previewingContext(_ previewingContext: UIViewControllerPreviewing, commit viewControllerToCommit: UIViewController) {
    if let chatDetailViewController = viewControllerToCommit as? ChatDetailViewController {
        chatDetailViewController.isReplyButtonHidden = false
    }

    show((viewControllerToCommit as UIController).viewControllers[0], sender: self)
}

show((viewControllerToCommit as UIController).viewControllers[0], sender: self)从导航控制器中提取视图控制器。这有什么缺点吗？

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1 回答 1

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在previewingContext(_:, viewControllerForLocation:)中，将您的视图控制器包装在 a 中UINavigationController并返回它。

于 2017-01-21T20:19:45.987 回答