是否有在 UIDocumentInteractionController 共享 sheet 弹出窗口之前调用的委托方法

Question

有人 help.I 可以在用户单击 pdf 查看器上的共享按钮后添加警告消息吗，我正在使用 UIDocumentInteractionController 预览 pdf 文档。我想知道是否有任何我可以覆盖的委托方法或函数，我可以在打开共享之前添加我的警报 sheet?[![在此处输入图片描述][1]][1]

class ViewController: UIViewController {
    
    var documentController : UIDocumentInteractionController!

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
    }

    @IBAction private func buttonTapped(_ sender: Any) {
        
       guard let fileURL = Bundle.main.url(forResource: "infomation", withExtension: "pdf") else {return}
        documentController = UIDocumentInteractionController.init(url: fileURL)
        documentController.delegate = self
        documentController.presentPreview(animated: true)
    }
}

extension ViewController: UIDocumentInteractionControllerDelegate {
    func documentInteractionControllerViewControllerForPreview(_ controller: UIDocumentInteractionController) -> UIViewController {
        
        return self
    }
    
    func documentInteractionControllerWillPresentOpenInMenu(_ controller: UIDocumentInteractionController) {
  
    }
    
    func documentInteractionControllerWillPresentOptionsMenu(_ controller: UIDocumentInteractionController) {
    
    }
    
    func documentInteractionController(_ controller: UIDocumentInteractionController, willBeginSendingToApplication application: String?) {
    
    }
}

但是当我点击共享按钮时，其中 none 会被调用，即使我已将委托设置为我的视图 controller.is 我有办法做到这一点吗？

Answer 1

解释：

如果不通过迭代所有子视图并覆盖按钮的操作和目标将其组合在一起，就无法做到这一点。

一种干净的方法是创建您自己的预览控制器，如下所示。如果您将 QLPreviewController 添加到 UINavigationController，它会自动创建一个您不需要的 bottom toolbar。要解决此问题，您可以将其添加为常规 UIViewController 的子控制器并创建自定义导航栏。

您还可以使用 UTI 作为 UIActivityItem 来确定项目的共享方式。我只实现了预览和基本共享功能，但其余的应该非常容易做到，至少它比 UIDocumentInteractionController 更可定制，因为您可以完全控制一切。

现在是执行所有这些操作的代码：

//
//  ViewController.swift
//  CustomDocumentController
//
//  Created by brandon on 2022-01-13.
//

import UIKit
import QuickLook
import MobileCoreServices
import UniformTypeIdentifiers

private class PreviewItem: NSObject, QLPreviewItem {
    var previewItemURL: URL?
    var previewItemTitle: String?
    
    init(title: String, url: URL) {
        super.init()
        
        previewItemURL = url
        previewItemTitle = title
    }
}

class DocumentInteractionController: UIViewController {
    
    private let url: URL
    
    private lazy var navigationBar: UINavigationBar = {
        let navigationBar = UINavigationBar()
        let navigationItem = UINavigationItem(title: name ?? "Document")
        navigationItem.hidesBackButton = true
        navigationItem.leftBarButtonItem = UIBarButtonItem(barButtonSystemItem: .done, target: self, action: #selector(onDone))
        navigationItem.rightBarButtonItem = UIBarButtonItem(barButtonSystemItem: .action, target: self, action: #selector(onShare)) //UIImage(systemName: "square.and.arrow.up")
        navigationBar.pushItem(navigationItem, animated: false)
        return navigationBar
    }()
    
    private lazy var previewController: QLPreviewController = {
        let previewController = QLPreviewController()
        previewController.title = name
        previewController.dataSource = self
        previewController.delegate = self
        previewController.reloadData()
        return previewController
    }()
    
    var uti: String? {
        didSet {
            previewController.reloadData()
        }
    }
    
    var name: String? {
        didSet {
            previewController.title = name
            navigationBar.topItem?.title = name
        }
    }
    
    init(url: URL) {
        self.url = url
        super.init(nibName: nil, bundle: nil)
        //super.init(rootViewController: self.previewController)
        self.modalPresentationStyle = .fullScreen
        
        name = (try? url.resourceValues(forKeys: [.localizedNameKey]))?.localizedName
        uti = (try? url.resourceValues(forKeys: [.typeIdentifierKey]))?.typeIdentifier
        
        if uti == nil {
            if #available(iOS 15.0, *) {
                uti = UTType.url.identifier
            } else {
                uti = String(kUTTypeURL)
            }
        }
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()

        addChild(previewController)
        previewController.didMove(toParent: self)
        
        let separator = UIView()
        separator.backgroundColor = .lightGray
        
        view.addSubview(navigationBar)
        view.addSubview(separator)
        view.addSubview(previewController.view)
        
        NSLayoutConstraint.activate([
            navigationBar.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor),
            navigationBar.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor),
            navigationBar.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
            
            separator.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor),
            separator.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor),
            separator.topAnchor.constraint(equalTo: navigationBar.bottomAnchor),
            separator.heightAnchor.constraint(equalToConstant: 1.0 / UIScreen.main.scale),
            
            previewController.view.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor),
            previewController.view.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor),
            previewController.view.topAnchor.constraint(equalTo: separator.bottomAnchor),
            previewController.view.bottomAnchor.constraint(equalTo: view.bottomAnchor)
        ])
        
        [navigationBar, separator, previewController.view].forEach({
            [=10=]?.translatesAutoresizingMaskIntoConstraints = false
        })
        
        navigationBar.barTintColor = previewController.view.backgroundColor
        view.backgroundColor = previewController.view.backgroundColor
    }
}

extension DocumentInteractionController: QLPreviewControllerDelegate, QLPreviewControllerDataSource {
    func numberOfPreviewItems(in controller: QLPreviewController) -> Int {
        return 1
    }
    
    func previewController(_ controller: QLPreviewController, previewItemAt index: Int) -> QLPreviewItem {
        return PreviewItem(title: name ?? "Document", url: url)
    }
}

extension DocumentInteractionController {
    @objc
    private func onDone() {
        self.dismiss(animated: true, completion: nil)
    }
    
    @objc
    private func onShare() {
        let activityViewController = UIActivityViewController(activityItems: [url],
                                                              applicationActivities: nil)
        
        activityViewController.excludedActivityTypes = [.assignToContact]
        if UIDevice.current.userInterfaceIdiom == .pad {
            activityViewController.popoverPresentationController?.sourceView = self.view
        }
        self.present(activityViewController, animated: true, completion: nil)
    }
}

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        
        let url = Bundle.main.url(forResource: "Testing", withExtension: ".md")
        let doc = DocumentInteractionController(url: url!)
        
        DispatchQueue.main.asyncAfter(deadline: .now() + 2.0) {
            self.present(doc, animated: true, completion: nil)
        }
    }
}

截图：

是否有在 UIDocumentInteractionController 共享 sheet 弹出窗口之前调用的委托方法

Is there a delegate method that gets called before the UIDocumentInteractionController share sheet pop ups

objective-c

ios

swift

uidocumentinteractioncontroller