public class ADUserModel
    {
        public string UserId { get; set; }
        public string UserName { get; set; }
        public string Email { get; set; }
    }

public static List<ADUserModel> GetAllDomainUserInfo()
        {
            List<ADUserModel> infolist = new List<ADUserModel>();
            string[] properties = new string[] { "fullname" };            
            System.DirectoryServices.DirectoryEntry adRoot = new System.DirectoryServices.DirectoryEntry("LDAP://" + PrimaryDomainName, DomainUser, DomainPassword, AuthenticationTypes.Secure);
            System.DirectoryServices.DirectorySearcher mySearcher = new System.DirectoryServices.DirectorySearcher(adRoot);
            mySearcher.Filter = "(objectClass=*)";
            mySearcher.PropertiesToLoad.Clear();
            SearchResultCollection searchResultCollection = null;
            try
            {
                searchResultCollection = mySearcher.FindAll();
                infolist = VisitSearchResultCollection(searchResultCollection);
            }
            catch
            {
                // 处理异常
            }            
            return infolist;
        }

 private static List<ADUserModel> VisitSearchResultCollection(SearchResultCollection resultCollection)
        {
            List<ADUserModel> domainlist = new List<ADUserModel>();
            StringBuilder html = new StringBuilder();
            foreach (SearchResult result in resultCollection)
            {
                string userName = string.Empty;
                string displayName = string.Empty;
                string distinguishedName = string.Empty;
                ADUserModel info = new ADUserModel();
                if (result.Properties.Contains("samaccountname"))
                {
                    ResultPropertyValueCollection resultValue = result.Properties["samaccountname"];
                    if (resultValue != null && resultValue.Count > 0 && resultValue[0] != null)
                    {
                        info.UserId = resultValue[0].ToString();
                        info.Email = info.UserId + "@aa.com";
                    }
                }
                if (result.Properties.Contains("mail"))
                {
                    ResultPropertyValueCollection resultValue = result.Properties["mail"];
                    if (resultValue != null && resultValue.Count > 0 && resultValue[0] != null)
                    {
                        info.Email = info.UserId + "@aa.com";
                    }
                }
                if (result.Properties.Contains("displayname"))
                {
                    ResultPropertyValueCollection resultValue = result.Properties["displayname"];
                    if (resultValue != null && resultValue.Count > 0 && resultValue[0] != null)
                    {
                        info.UserName = resultValue[0].ToString();
                    }
                }
                if (!string.IsNullOrEmpty(info.UserId))
                {
                    domainlist.Add(info);
                }
            }
            return domainlist;
        }

  using (MySqlConnection conn = new MySqlConnection(ConfigurationManager.AppSettings["redmineconn"]))
            {
                conn.Open();
                using (MySqlTransaction tran = conn.BeginTransaction() as MySqlTransaction)
                {
                    try
                    {
                        foreach (ADUserModel adUser in adUserList)
                        {
                            RedUserDal.Instance.InsertUser(adUser, conn, tran);
                        }
                        tran.Commit();
                    }
                    catch (Exception ex)
                    {
                        tran.Rollback();
                        Logger.Error(ex.Message);
                    }
                }
                conn.Close();
                conn.Dispose();
            }