如何启用从UIDocumentPickerViewController中选择文件的功能？

Question

我正在将文件附加到电子邮件，我想通过UIDocumentPickerViewController来完成。基本上，用户单击该图标即可选择文件。一切正常，用户可以选择一个文件，我可以获取它的URL，然后进行文件传输。最近它停止工作，而且令人惊讶的是，我没有对代码进行任何更改（是的，听起来很傻）。我发现的是没有调用我的didPickDocumentAt委托。总而言之，单击时会调用browserFiles函数，并显示documentBrowser，但选择文件不起作用（未调用didPickDocumentAt委托函数和uploadDataFromUrl）

extension EditViewTableViewController: UIDocumentMenuDelegate, UIDocumentPickerDelegate {
func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentAt url: URL) {
    self.uploadDataFromUrl(url: url)
}

public func documentMenu(_ documentMenu: UIDocumentMenuViewController, didPickDocumentPicker documentPicker: UIDocumentPickerViewController) {
    documentPicker.delegate = self
    present(documentPicker, animated: true, completion: nil)
}

func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
    dismiss(animated: true, completion: nil)
}

func browseFiles() {
    let documentBrowserController = UIDocumentPickerViewController(documentTypes: [kUTTypeImage, kUTTypeCompositeContent] as [String], in: UIDocumentPickerMode.import)
    if #available(iOS 11.0, *) {
        documentBrowserController.allowsMultipleSelection = true
    }
    documentBrowserController.delegate = self
    self.present(documentBrowserController, animated: false, completion: nil)
}

func uploadDataFromUrl(url: URL) {
    if FileManager.default.fileExists(atPath: url.path) {
        do {
            let data = try Data(contentsOf: url)
            self.didUploadedTheFile(path: url.path)
        } catch {
            print(error.localizedDescription)
        }
    }
}