本文转自: https://www.cnblogs.com/i-mengli/p/9625551.html 
        //获取登陆页输入的域账号、密码
        string domainIP = "192.168.12.10";      //域IP
        string userAccount = "Administrator";    //域账号
        string Password = "glyszsuzhou";      //域账号密码          
        using (DirectoryEntry deUser = new DirectoryEntry(@"LDAP://" + domainIP, userAccount, Password))
        {
            DirectorySearcher src = new DirectorySearcher(deUser);
            src.Filter = "(&(&(objectCategory=person)(objectClass=user))(sAMAccountName=" + userAccount + "))";
            src.PropertiesToLoad.Add("cn");
            src.SearchRoot = deUser;
            src.SearchScope = SearchScope.Subtree;
            SearchResult result = src.FindOne();
            if (result != null)//验证成功
            {
                DirectoryEntry de = result.GetDirectoryEntry();
                string userID = de.Username;
                #region 域账号验证通过......Read More>