/// <summary>
/// Check if the user has already logged in
/// </summary>
/// <returns>username string if success, otherwise null</returns>
private static string GetLoggedInUsername()
{
// first check if 'username' variable is in session
if (HttpContext.Current.Session[UsernameAccessString] != null)
{
string username = (string)HttpContext.Current.Session[UsernameAccessString];
// now check for the 'username' in the database for additional check
DataTable loginUserTable = DataAccessLayer.SelectCommand(DataAccessLayer.SelectCommandString(
"Username", LoginTable, "Username = :username"),
new CommandParameter(":username", username));
if (1 == loginUserTable.Rows.Count)
{
return(username);
}
// clear session state because it is not available in the database
HttpContext.Current.Session.Clear();
CurrentInstance.Reset();
}
return(null);
}
