2012-11-28 22 views
1

當我嘗試使用Google Drive .Net Api檢索元數據時,我能夠檢索文檔標題,但DownloadUrl for File是空的,因爲如果我上傳新文件,那麼它可用。DownloadUrl對於某些文件的文件爲空

這是我使用的代碼..

Try 
      Dim authenticator As IAuthenticator = TryCast(Session("authenticator"), IAuthenticator) 
      Dim service As DriveService = TryCast(Session("Service"), DriveService) 
      If authenticator Is Nothing OrElse service Is Nothing Then 
       Return Json("Failed Authenticator", JsonRequestBehavior.AllowGet) 
      End If 
      Dim file As Google.Apis.Drive.v2.Data.File = service.Files.Get(file_id).Fetch() 
       Return Json(file.DownloadUrl, JsonRequestBehavior.AllowGet) 
     Catch ex As Exception 
      Return Json(ex.Message, JsonRequestBehavior.AllowGet) 
     End Try 

回答