how to download file form Google Drive asp.net - google-drive-api

Question

I am trying to download files from google drive below is my code
private static IAuthenticator CreateAuthenticator()
{
var provider = new NativeApplicationClient(GoogleAuthenticationServer.Description);
provider.ClientIdentifier = ClientCredentials.CLIENT_ID;
provider.ClientSecret = ClientCredentials.CLIENT_SECRET;
return new OAuth2Authenticator<NativeApplicationClient>(provider, GetAuthorization);
}
public static System.IO.Stream DownloadFile(
IAuthenticator authenticator, Google.Apis.Drive.v2.Data.File file)
{
if (!String.IsNullOrEmpty(file.DownloadUrl))
{
try
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(
new Uri(file.DownloadUrl));
authenticator.ApplyAuthenticationToRequest(request);
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
if (response.StatusCode == HttpStatusCode.OK)
{
return response.GetResponseStream();
}
else
{
Console.WriteLine(
"An error occurred: " + response.StatusDescription);
return null;
}
}
catch (Exception e)
{
Console.WriteLine("An error occurred: " + e.Message);
return null;
}
}
else
{
// The file doesn't have any content stored on Drive.
return null;
}
}
in .aspx page code
{
System.IO.Stream stream = Utilities.DownloadFile(CreateAuthenticator(), FIle);
//Convert the stream to an array of bytes.
System.IO.BinaryReader br = new System.IO.BinaryReader(stream);
Byte[] byteArray = br.ReadBytes((int)stream.Length);
its showing This stream does not support seek operations.
where is error
thank u....

Answer 1

You do not have to seek the file if you are trying just to download the file. What you should do is just to read the stream i.e. through the DownloadFile API method and pass it to the browser. I have enable it through the following code:
public FileResult DownloadFile(string fileId)
{
DriveService service = Session["service"] as DriveService;
Google.Apis.Drive.v2.Data.File file = service.Files.Get(fileId).Fetch();
System.IO.Stream data = new GDriveRepository(Utils.ReturnIAuth((GoogleAuthenticator)Session["Gauthenticator"])).DownloadFile(file.DownloadUrl);
return File(data, System.Net.Mime.MediaTypeNames.Application.Octet, file.Title);
}