How to get List of spreadsheet from google drive?

Question

Hello Friends,

        I need to get the list of spreadsheet with data available in Google drive by using c# language.
        I was using the following code,

SpreadsheetsService

service = new SpreadsheetsService("GDriveSpreadSheet"); ;

                service.setUserCredentials(

"UserName", "password");

SpreadsheetQuery Q = new SpreadsheetQuery();

SpreadsheetFeed F = service.Query(Q);

SpreadsheetEntry spreadsheet = (SpreadsheetEntry)F.Entries[0];

WorksheetFeed wsFeed = spreadsheet.Worksheets;

But I'm getting invalid Credential exception in the above marked line...

Can any one help me!!!

Thanks