多对多的Entity Framework GetUsersInRole（）

Question

I have two Entity types: Role and User that have many to many relation. That is Role has the Users property, and User has the Roles property. I must get the string array with usernames that belong to defined role. I wrote some code, but it is not elegant. I want do that with one linq expression. Is it possible?

public override string[] GetUsersInRole(string roleName)
{
    List<string> names = new List<string>();
    using (MembershipDb db = new MembershipDb())
    {
        Role role = db.Roles.FirstOrDefault(r => r.Name == roleName);
        foreach (User u in role.Users)
        {
            names.Add(u.UserName);
        }
    }
    return names.ToArray();
}

Answer 1

Look at this:

public override string[] GetUsersInRole(string roleName)
{
    using (MembershipDb db = new MembershipDb())
    {
        return db.Roles
           .Where(r => r.Name == roleName)
           .SelectMany(r => r.Users, (r, s) => s.User.UserName).ToArray();
    }
}

Answer 2

return db.Roles.Where(r => r.Name == roleName)
               .SelectMany(r => r.Users)
               .Select(u => u.UserName)
               .ToArray();