Getting the current user id (not name) using forms authentication?

Question

Question:

I\'m playing around with forms authentication and my own custom membership provider.

From what I see, I can get the current FormsIdentity by doing:

Answer 1

Yes, one can with a workaround from here.
One can set the UserId in the Auth cookie-Ticket UserData.

public class UserData
{
    public string FirstName { get; set; }
    public UserData()
    {
        FirstName = "Unknown";
    }
} // End Class UserData



public void SignIn(string userName, bool createPersistentCookie)
{
    if (String.IsNullOrEmpty(userName)) 
        throw new ArgumentException("Der Wert darf nicht NULL oder leer sein.", "userName");

    UserData userData = new UserData();
    SetAuthCookie(userName, createPersistentCookie, userData);
    //FormsAuthentication.SetAuthCookie(userName, createPersistentCookie);
}


public void SetAuthCookie(string userName, bool createPersistentCookie, UserData userData)
{
    HttpCookie cookie = FormsAuthentication.GetAuthCookie(userName, createPersistentCookie);
    FormsAuthenticationTicket ticket = FormsAuthentication.Decrypt(cookie.Value);
    FormsAuthenticationTicket newTicket = new FormsAuthenticationTicket(
         ticket.Version, ticket.Name, ticket.IssueDate, ticket.Expiration
        ,ticket.IsPersistent, userData.ToJSON(), ticket.CookiePath
    );

    string encTicket = FormsAuthentication.Encrypt(newTicket);
    cookie.Value = encTicket;
    System.Web.HttpContext.Current.Response.Cookies.Add(cookie);
} // End Sub SetAuthCookie

Another possibility is to just use the UserId.ToString() as "name".