GDrive文件夹创建

Question

如何在Swift iOS的GDrive中创建文件夹？ Google登录成功，但无法创建文件夹。我遇到错误-

  

“发生错误：错误Domain = com.google.GTLRErrorObjectDomain代码= 401“需要登录” UserInfo = {GTLRStructuredError = GTLRErrorObject 0x600000054730：{消息：“需要登录”错误：[1]代码：401}，NSLocalizedDescription =需要登录}   （lldb）“。

请帮助。

这是我正在使用的代码。

let metadata = GTLRDrive_File()
metadata.name = "Sample"
metadata.mimeType = "application/vnd.google-apps.folder"
let query = GTLRDriveQuery_FilesCreate.query(withObject: metadata, uploadParameters: nil)
query.fields = "id"
let driveService = GTLRDriveService()
driveService.apiKey = "XXXXXXXXXXXXXXX"
driveService.executeQuery(query, completionHandler: { ticket, file, error in
    if error == nil {

    } else {
        if let anError = error {
            print("An error occurred: \(anError)")
        }
    }
})