C# 访问AD查询用户信息

string[] ldapSearchUserArr = new string[] { "userprincipalname", "userAccountControl", "sAMAccountName", "mail" };
            using (DirectoryEntry adminEntry = new DirectoryEntry(ldapUrl, andminusername, adminpassword, AuthenticationTypes.Secure))
            {
                DirectorySearcher userSearch = new DirectorySearcher(adminEntry);
                userSearch.SearchScope = SearchScope.Subtree;
                userSearch.Filter = "(&(objectCategory=person)(objectClass=user)(sAMAccountName=" + username + "))";
                userSearch.PropertiesToLoad.AddRange(ldapSearchUserArr);
                SearchResult searchResult = userSearch.FindOne();
                if (searchResult != null)
                {
                    //dosomething...
                }
            }