Abstractions.WindowsApi.pInvokes.GetInteractiveUserList C# (CSharp) Метод

        public static List<string> GetInteractiveUserList()
        {
            List<string> result = new List<string>();

            IntPtr sessionInfoList = IntPtr.Zero;
            int sessionCount = 0;
            int retVal = SafeNativeMethods.WTSEnumerateSessions(SafeNativeMethods.WTS_CURRENT_SERVER_HANDLE, 0, 1, ref sessionInfoList, ref sessionCount);
            if(retVal != 0)
            {
                int dataSize = Marshal.SizeOf(typeof(SafeNativeMethods.WTS_SESSION_INFO));
                int currentSession = (int) sessionInfoList;

                for(int x = 0; x < sessionCount; x++)
                {
                    SafeNativeMethods.WTS_SESSION_INFO sessionInfo = (SafeNativeMethods.WTS_SESSION_INFO)Marshal.PtrToStructure((IntPtr)currentSession, typeof(SafeNativeMethods.WTS_SESSION_INFO));
                    currentSession += dataSize;

                    uint bytes = 0;
                    IntPtr userInfo = IntPtr.Zero;
                    IntPtr domainInfo = IntPtr.Zero;
                    bool sResult = SafeNativeMethods.WTSQuerySessionInformation(SafeNativeMethods.WTS_CURRENT_SERVER_HANDLE, sessionInfo.SessionID, SafeNativeMethods.WTS_INFO_CLASS.WTSUserName, out userInfo, out bytes);
                    if (!sResult)
                    {
                        LibraryLogging.Error("GetInteractiveUserList() WTSQuerySessionInformation WTSUserName Error:{0}", LastError());
                    }
                    string user = Marshal.PtrToStringAnsi(userInfo);
                    SafeNativeMethods.WTSFreeMemory(userInfo);
                    /*
                    sResult = SafeNativeMethods.WTSQuerySessionInformation(SafeNativeMethods.WTS_CURRENT_SERVER_HANDLE, sessionInfo.SessionID, SafeNativeMethods.WTS_INFO_CLASS.WTSDomainName, out domainInfo, out bytes);
                    if (!sResult)
                    {
                        LibraryLogging.Error("GetInteractiveUserList() WTSQuerySessionInformation WTSDomainName Error:{0}", LastError());
                    }
                    string domain = Marshal.PtrToStringAnsi(domainInfo);
                    SafeNativeMethods.WTSFreeMemory(domainInfo);
                    */
                    /*
                    if (!string.IsNullOrEmpty(domain))
                    {
                        result.Add(string.Format("{0}\\{1}", domain, user));
                    }*/
                    if (!string.IsNullOrEmpty(user))
                    {
                        result.Add(string.Format("{0}\\{1}", sessionInfo.SessionID, user));
                    }
                }

                SafeNativeMethods.WTSFreeMemory(sessionInfoList);
            }
            //LibraryLogging.Info("InteractiveUsers:{0}", String.Join<string>(", ", result));

            return result;
        }