问基于文档的应用程序

EN

@IBOutlet weak var documentNameLabel: UILabel!

var document: UIDocument?

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    // Access the document
    document?.open(completionHandler: { (success) in
        if success {
            // Display the content of the document, e.g.:
            self.documentNameLabel.text = self.document?.fileURL.lastPathComponent

            // --> How to show/load the pdf here? Do I have to create a UIView here first?

        } else {
            // Make sure to handle the failed import appropriately, e.g., by presenting an error message to the user.
        }
    })
}

var pdfData: PreviewViewController?

override func contents(forType typeName: String) throws -> Any {
    // Encode your document with an instance of NSData or NSFileWrapper
    return Data()

}

override func load(fromContents contents: Any, ofType typeName: String?) throws {
   // --> do I have to load the pdf here?
}