C# - Extend AuthorizeAttribute And Check The User's Roles?

I am busy writing my own custom attribute for my action method called MyAuthorizeAttribute, I am still busy writing the code, here is my partial code:

[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
public class MyAuthorizeAttribute : AuthorizeAttribute
{
public new Role Roles;
public override void OnAuthorization(AuthorizationContext filterContext)
{
base.OnAuthorization(filterContext);
if (Roles != 0) // Did it this way to see what the value of Roles was
return;
// Here I am going to get a list of user roles
// I'm doing my own database calls
filterContext.Result = new HttpUnauthorizedResult();
}
}

Here is my Role enum:

public enum Role
{
Administrator = 1,
SuperAdministrator = 2
}

My action method:

[MyAuthorize(Roles = Role.Administrator|Role.SuperAdministrator)]
public ActionResult Create()
{
return View();
}

The reason why I did not use Roles = "Administrator,SuperAdministrator" was because the roles are hard-coded. I don't want to have a 100 places to change if the role name changes.

Given my method, when it gets to if (Roles != 0) then Roles total value is 3, how would I check to see if these 2 roles is in the list of user roles for a specific user?

Am I doing it correct here? If not how would I otherwise implement this? It doesn't have to be the way that I did it in.