How I keep entity object after DataContext disposed?

I use this style when I get data from database

public class User
{
    public static List<User> GetUsers()
    {
        List<User> users = new Users();
        using ( var context = new DataContext())
        {
            users = context.Users.ToList();
        }

        return users;
    }
}

After I get data from database then I want to Filter user likes this

List<开发者_Go百科;User> userResultList = User.GetUsers();   
userResultList.Where(u => u.IsActive == true);

But cannot filter and I get this error

The ObjectContext instance has been disposed and can no longer be used for operations that require a connection.

My Question : Is possible way to filter result object after DataContext disposed?

Thank you very much for every support.

Update !!!

I think it possible if I create new DbContext in method scope that I want to retrieve data

Is it good enough approach?

Example

public class User
    {
        public static List<User> GetUsers()
        {
            List<User> users = new Users();

            var context = new DataContext())
            users = context.Users.ToList();

            return users;
        }
    }

I wonder if you clone the list will get around the error?

User[] L = new User[users.Count];
users.CopyTo(L);

Speculation:

What you had looks like it should work on the surface.

I wonder if the thing that is returned by ToList() is something that inherits from list, and retains some hidden context awareness inside.

I can't test this idea right now. Something to think about for later though.