Active Directory Account Manager

gistfile1.cs

using System.DirectoryServices.AccountManagement;
......

 using (PrincipalContext pc = new PrincipalContext(ContextType.Domain, ADDomain))
            {
                var user = UserPrincipal.FindByIdentity(pc, IdentityType.SamAccountName, ADDomain + "\\" + username);
                var group = GroupPrincipal.FindByIdentity(pc, "Admins. del dominio");
                var y = user.IsMemberOf(group);

                var z = user.GetGroups().ToList();

                // validate the credentials
                return pc.ValidateCredentials(username, password);

            }