public Boolean ValidateDomainUser(string Domain, string UserName, string Password)
        {
            DirectoryEntry entry = new DirectoryEntry(Domain, UserName, Password);
            try
            {
                string objectSid = (new SecurityIdentifier((byte[])entry.Properties["
 
objectSid"].Value, 0).Value);//如果賬號不對則會拋出異常
                return true;
            }
            catch
            {
                return false;
            }
            finally
            {
                entry.Dispose();
            }
        }

//代碼調用，LDAP一定要大寫。
MessageBox.Show(ValidateDomainUser("
 
LDAP://域控的IP地址/DC=ha-ad,DC=net", "evan", "evan的密碼").ToString());

C#學習筆記-域用戶認證（一）