Your favorite "current user"-pattern for Asp.net applications?

Question

What is the nicest pattern you have seen or used for accessing the current logged on user in an Asp.NET application?

Current user refers to the business object that represents a user in your system, be it a membership user object or a custom class. The user object should be easy to reach within places like global (httpapplication object), web forms, controllers, webhandlers etc. It is probably be sent to the back end layers of the project and sometimes injected in other business objects depending on your application.

Requirements:

• Working nicely in both MVC and WebForms.
• The pattern should be able to work with either aspnet membership classes or own classes being "users".
• Clear and obvious way of dealing with when not being logged in.

Answer 1

I am actually quite happy with what's already built-in ASP.NET:

if (User.Identity.IsAuthenticated)
{
    string currentlyLoggedUsername = User.Identity.Name;
    // TODO: Now given this username you could query your repository
    // or the Membership provider to fetch additional user information.
}

Answer 2

Here's what I do to store an object instead of a name which I find less useful.

In my account controller:

    public static User CacheUserInSession(User user)
    {
        Contract.Assert(user != null);

        if (user == null) // Not found, name may have changed
        {
            new FormsAuthenticationService().SignOut();
        }
        else
        {
            // Save off the user for later use by other classes
            ContextCache<User>.Set(user, ContextCache.AspNetUserSessionCache);
            ContextCache<int>.Set(user.RowId, ContextCache.UserIdSessionCache);
        }

        return user;
    }

    public static User GetUserFromSession()
    {
        var user = ContextCache<User>.Get(ContextCache.AspNetUserSessionCache);

        return user;
    }

My cache class:

public class ContextCache<T>
{    
    public static void Set(T objectToCache, string key)
    {
        System.Web.HttpContext.Current.Items.Add(key, objectToCache);
    }

    public static T Get(string key)
    {
        return (T)System.Web.HttpContext.Current.Items[key];
    }

}

I call CacheUserInSession from Application_AuthenticateRequest passing in my User object/model which I read from the database.

When I want to retrieve the user, I make this call:

var user = AccountController.GetUserFromSession();

Using the cache wrapper, you can store/retrieve any kind of object you want.

No mess. No fuss.