How to fetech documents from google drive using asp.net

Question

DocumentsService d_service = new DocumentsService("Auth_test_app"); 

d_service.setUserCredentials("username", "password");

DocumentsListQuery query = new DocumentsListQuery();
DocumentsFeed feed = d_service.Query(query);
var docs = new List<string>();
foreach (DocumentEntry entry in feed.Entries)
{
Console.WriteLine(entry.Title.Text);

}

 

 

Getting error plz helpme