iOS12: transitionController已弃用

Question

我有一个基于UIDocumentBrowser的应用程序，打开一个特定类型的文件。打开文件的默认过渡是从底部滑动，这不是用户所能期望的最好的过渡。在iOS 12之前，你可以得到一个缩放过渡，现在它也可以工作了，但是编译器抱怨使用的transitionController(forDocumentURL:)已经被弃用了。如何在iOS 12 way中实现此效果？

func presentDocument(at documentURL: URL) {
    let storyBoard = UIStoryboard(name: "Main", bundle: nil)
    let documentViewController = storyBoard.instantiateViewController(withIdentifier: "MainViewController") as! MainViewController
    documentViewController.document = Document(fileURL: documentURL)
    // 
    documentViewController.transitioningDelegate = self
    let transitioningController = transitionController(forDocumentURL: documentURL)
    transitioningController.targetView = documentViewController.view
    self.transitioningController = transitioningController
    //
    present(documentViewController, animated: true, completion: nil)
}

Answer 1

我相信这个参数刚刚被改变了，你可以用forDocumentAt替换forDocumentURL

let transitioningController = transitionController(forDocumentAt: documentURL)