如何解决关闭文档选择器时出现的错误

Question

设置文档选择器，用户可以从“文件应用程序”中选择 PDF 文件，并将其保存到我的应用程序文档文件夹中以在应用程序中使用。

打开文档选择器，选择文件 - 但关闭后出现以下错误：

“[DocumentManager] 视图服务确实终止并出现错误：Error Domain=_UIViewServiceErrorDomain Code=1 “(null)”UserInfo={Termminate=disconnect method}”

UIViewController代码：

import UIKit
import CoreData
import PDFKit
import MobileCoreServices
import UniformTypeIdentifiers


class AddDocumentViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate, UIDocumentPickerDelegate {



@IBAction func chooseFile (_ sender: UIButton) {
    fileTypeSelectionInput = fileTypeSelection.selectedSegmentIndex
    
        var documentPicker: UIDocumentPickerViewController!
        if #available(iOS 14, *) {
            // iOS 14 & later
            let supportedTypes: [UTType] = [UTType.pdf]
            documentPicker = UIDocumentPickerViewController(forOpeningContentTypes: supportedTypes)
        } else {
            // iOS 13 or older code
            let supportedTypes: [String] = [kUTTypeImage as String]
            documentPicker = UIDocumentPickerViewController(documentTypes: supportedTypes, in: .import)
        }
        documentPicker.delegate = self
        documentPicker.allowsMultipleSelection = false
        documentPicker.modalPresentationStyle = .formSheet
        self.present(documentPicker, animated: true) 
}


func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {

    let fileURL = urls[0]
    var fileName = urls[0].lastPathComponent
    subjectFileName = fileName
    let filePath = getDocumentsDirectory().appendingPathComponent(fileName)
    print(fileName)
    
    guard fileURL.startAccessingSecurityScopedResource() else {
            // Handle denied access

            return
        }
        defer { fileURL.stopAccessingSecurityScopedResource() }

        do {
            guard let document = PDFDocument(url: fileURL) else {
                    print("Error: could not create PDFDocument from url")
                    return
                }
          document.write(to: filePath)
            print ("success")
        } catch let error {
            print("error: \(error)")
        }

}



func getDocumentsDirectory() -> URL {
    let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
    return paths[0]
}

}

我已经查过这个错误，但似乎无法纠正。这与 iCloud 功能有关吗？如果是这样，这是因为文件文档可能位于个人 iCloud 上吗？因为我不打算将任何文档保存到 iCloud，只保存到应用程序文档文件夹。

如果此错误是由于 iCloud 造成的，我已按照 Apple 文档进行操作：https: //developer.apple.com/documentation/xcode/configuring-icloud-services

并设置如下：

我注意到 iCloud 功能是

但是错误仍然显示。有任何想法吗？提前致谢