Using Linq on MembershipUserCollection

Question

I have this code which gives me a list of all the users by using my membership provider.

        var users = Membership.GetAllUsers();
        var usernames = new List<string>();
        foreach(MembershipUser m in users)
            usernames.Add(m.UserName);

I thought there should be an easier way to do this by using LINQ, but I can't seem to use LINQ on a MembershipUserCollection

Answer 1

Because MembershipUserCollection only implements IEnumerable, not IEnumerable<MembershipUser>, you need to use the Linq extension method Cast then then use other Linq extension methods:

Membership.GetAllUsers ().Cast<MembershipUser> ().Select (m => m.UserName);

Answer 2

You should be able to use LINQ, if you use the Cast<T>() method on it first.

Like this:

var usernames = Membership.GetAllUsers().Cast<MembershipUser>().Select(x => x.UserName).ToList();

Answer 3

Generally an alternative to explicit casting is to use

OfType<MembershipUser>

so you have

var userList = Membership.GetAllUsers().OfType<MembershipUser>().ToList();