如何访问应用程序特定文件夹并使用它来备份或某些应用程序特定数据？迅速

我想创建一个应用程序，其中某些类型的数据将同步到应用程序特定文件夹中的谷歌驱动器，并且可以进一步访问它以检索数据并填充到应用程序中。如果不知何故用户的手机丢失并且用户使用另一部手机，并且当用户登录同一谷歌帐户时，应该获取该数据。

My problem is I am not aware the steps to follow to do this, I am able to create the app folder over google drive and this is showing to end user over drive

现在，当我尝试在其中插入数据时出现范围错误。 我使用的代码是：

import Foundation
import GoogleAPIClientForREST

enum GDriveError: Error {
    case NoDataAtPath
 }

class ATGoogleDrive {

private let service: GTLRDriveService

init(_ service: GTLRDriveService) {
    self.service = service
}

public func listFilesInFolder(_ folder: String, onCompleted: @escaping (GTLRDrive_FileList?, Error?) -> ()) {
    search(folder) { (folderID, error) in
        guard let ID = folderID else {
            onCompleted(nil, error)
            return
        }
        self.listFiles(ID, onCompleted: onCompleted)
    }
}

private func listFiles(_ folderID: String, onCompleted: @escaping (GTLRDrive_FileList?, Error?) -> ()) {
    let query = GTLRDriveQuery_FilesList.query()
    query.pageSize = 100
    query.q = "'\(folderID)' in parents"

    service.executeQuery(query) { (ticket, result, error) in
        onCompleted(result as? GTLRDrive_FileList, error)
    }
}

public func uploadFile(_ folderName: String, data: Data, MIMEType: String, onCompleted: ((String?, Error?) -> ())?) {

    search("config.json") { (folderID, error) in

        if let ID = folderID {
            self.upload(ID, data: data, MIMEType: MIMEType, onCompleted: onCompleted)
        } else {
            self.createFolder(folderName, onCompleted: { (folderID, error) in
                self.upload("", data: data, MIMEType: MIMEType, onCompleted: onCompleted)
            })
        }
    }
}

private func upload(_ parentID: String, data: Data, MIMEType: String, onCompleted: ((String?, Error?) -> ())?) {

    let metadata: GTLRDrive_File = GTLRDrive_File()
    metadata.name = "config.json"
    metadata.parents = ["appDataFolder"]

    let uploadParameters: GTLRUploadParameters = GTLRUploadParameters(data: data, mimeType: "application/json") 
    uploadParameters.shouldUploadWithSingleRequest = true;
    let query: GTLRDriveQuery_FilesCreate = GTLRDriveQuery_FilesCreate.query(withObject: metadata, uploadParameters: uploadParameters)//[GTLRDriveQuery_FilesCreate queryWithObject:metadata
     query.fields = "id"
     self.service.executeQuery(query) { (ticket, fileN, error) in
        print(ticket)
        print(fileN)
        print(error)
        if let f = fileN as? GTLRDrive_File {
            if (error == nil) {
                print("File ID %@", f.identifier);
            } else {
                print("An error occurred: %@", error);
            }
        } 
      }
    }

public func listFromAppFolder(_ parentID: String, data: Data, MIMEType: String, onCompleted: ((String?, Error?) -> ())?) {
    let file = GTLRDrive_File()
    file.name = "\(Date().timeIntervalSince1970)"
    file.parents = ["appfolder"]

    let uploadParams = GTLRUploadParameters.init(data: data, mimeType: MIMEType)
    uploadParams.shouldUploadWithSingleRequest = true

    let query = GTLRDriveQuery_FilesCreate.query(withObject: file, uploadParameters: uploadParams)
    query.fields = "id"

    self.service.executeQuery(query, completionHandler: { (ticket, file, error) in
        print(ticket)
        print(file)
        print(error)
        onCompleted?((file as? GTLRDrive_File)?.identifier, error)
    })
}

public func download(_ fileID: String, onCompleted: @escaping (Data?, Error?) -> ()) {
    let query = GTLRDriveQuery_FilesGet.queryForMedia(withFileId: fileID)
    service.executeQuery(query) { (ticket, file, error) in
        onCompleted((file as? GTLRDataObject)?.data, error)
    }
}

public func search(_ fileName: String, onCompleted: @escaping (String?, Error?) -> ()) {
    let query = GTLRDriveQuery_FilesList.query()
    query.pageSize = 1
    query.q = "name contains '\(fileName)'"

    service.executeQuery(query) { (ticket, results, error) in
        onCompleted((results as? GTLRDrive_FileList)?.files?.first?.identifier, error)
    }
}

public func createFolder(_ name: String, onCompleted: @escaping (String?, Error?) -> ()) {
    let file: GTLRDrive_File = GTLRDrive_File()
    file.name = "config.json"
    file.parents = ["appfolder"]
    let query = GTLRDriveQuery_FilesCreate.query(withObject: file, uploadParameters: nil)
    query.fields = "id"

    service.executeQuery(query) { (ticket, folder, error) in
        onCompleted((folder as? GTLRDrive_File)?.identifier, error)
    }
}

public func delete(_ fileID: String, onCompleted: ((Error?) -> ())?) {
    let query = GTLRDriveQuery_FilesDelete.query(withFileId: fileID)
    service.executeQuery(query) { (ticket, nilFile, error) in
        onCompleted?(error)
    }
  }
 }

并用于登录并使用下面的类

import UIKit
import GoogleSignIn
import GoogleAPIClientForREST

class ViewController: UIViewController {

@IBOutlet weak var resultsLabel: UILabel!

fileprivate let service = GTLRDriveService()
private var drive: ATGoogleDrive?

override func viewDidLoad() {
    super.viewDidLoad()

    setupGoogleSignIn()

    drive = ATGoogleDrive(service)

    view.addSubview(GIDSignInButton())
}

private func setupGoogleSignIn() {
    GIDSignIn.sharedInstance().delegate = self
    GIDSignIn.sharedInstance().uiDelegate = self
    GIDSignIn.sharedInstance().scopes = [kGTLRAuthScopeDriveFile]
    GIDSignIn.sharedInstance().signInSilently()
}


@IBAction func uploadAction(_ sender: Any) {
    if let documentsDir = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last {
        let dataImg: Data = UIImageJPEGRepresentation(UIImage(named: "logo.png")!, 1.0)!
        drive?.uploadFile("config.json", data: dataImg, MIMEType: "image/png") { (fileID, error) in
            print("Upload file ID: \(fileID); Error: \(error?.localizedDescription)")
        }
       }
     }

    @IBAction func listAction(_ sender: Any) {
    drive?.listFilesInFolder("config.json") { (files, error) in
        guard let fileList = files else {
            print("Error listing files: \(error?.localizedDescription)")
            return
        }

        self.resultsLabel.text = fileList.files?.description
        print(fileList)
        for nFile in fileList.files! {
            if nFile.mimeType == "image/jpeg" {
                self.drive?.download(nFile.identifier!, onCompleted: { (data, error) in
                    print(data)
                    print(error)
                })
              }
            }
          }
        }
      }

     // MARK: - GIDSignInDelegate
     extension ViewController: GIDSignInDelegate {
     func sign(_ signIn: GIDSignIn!, didSignInFor user: GIDGoogleUser!, withError error: Error!) {
    if let _ = error {
        service.authorizer = nil
    } else {
        service.authorizer = user.authentication.fetcherAuthorizer()
        service.shouldFetchNextPages = true
    }
  } 
 }

    // MARK: - GIDSignInUIDelegate
    extension ViewController: GIDSignInUIDelegate {}

每当我尝试上传任何文件时，都会出现错误：

Error Domain=com.google.GTLRErrorObjectDomain Code=403 "The granted scopes do not allow use of the Application Data folder." UserInfo={GTLRStructuredError=GTLRErrorObject 0x281515d10: {message:"The granted scopes do not allow use of the Application Data folder." errors:[1] code:403}, NSLocalizedDescription=The granted scopes do not allow use of the Application Data folder.}

您需要设置谷歌驱动器配置的范围，

GIDSignIn.sharedInstance().scopes = [kGTLRAuthScopeDriveAppData]

参考 驱动范围 https://developers.google.com/drive/api/v3/about-auth#what-scope-or-scopes-does-my-app-need-?