问如何在.NET中检索已登录/已连接用户的列表？

EN

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;

namespace EnumerateRDUsers
{
  class Program
  {
    [DllImport("wtsapi32.dll")]
    static extern IntPtr WTSOpenServer([MarshalAs(UnmanagedType.LPStr)] string pServerName);

    [DllImport("wtsapi32.dll")]
    static extern void WTSCloseServer(IntPtr hServer);

    [DllImport("wtsapi32.dll")]
    static extern Int32 WTSEnumerateSessions(
        IntPtr hServer,
        [MarshalAs(UnmanagedType.U4)] Int32 Reserved,
        [MarshalAs(UnmanagedType.U4)] Int32 Version,
        ref IntPtr ppSessionInfo,
        [MarshalAs(UnmanagedType.U4)] ref Int32 pCount);

    [DllImport("wtsapi32.dll")]
    static extern void WTSFreeMemory(IntPtr pMemory);

    [DllImport("wtsapi32.dll")]
    static extern bool WTSQuerySessionInformation(
        IntPtr hServer, int sessionId, WTS_INFO_CLASS wtsInfoClass, out IntPtr ppBuffer, out uint pBytesReturned);

    [StructLayout(LayoutKind.Sequential)]
    private struct WTS_SESSION_INFO
    {
      public Int32 SessionID;

      [MarshalAs(UnmanagedType.LPStr)]
      public string pWinStationName;

      public WTS_CONNECTSTATE_CLASS State;
    }

    public enum WTS_INFO_CLASS
    {
      WTSInitialProgram,
      WTSApplicationName,
      WTSWorkingDirectory,
      WTSOEMId,
      WTSSessionId,
      WTSUserName,
      WTSWinStationName,
      WTSDomainName,
      WTSConnectState,
      WTSClientBuildNumber,
      WTSClientName,
      WTSClientDirectory,
      WTSClientProductId,
      WTSClientHardwareId,
      WTSClientAddress,
      WTSClientDisplay,
      WTSClientProtocolType
    }

    public enum WTS_CONNECTSTATE_CLASS
    {
      WTSActive,
      WTSConnected,
      WTSConnectQuery,
      WTSShadow,
      WTSDisconnected,
      WTSIdle,
      WTSListen,
      WTSReset,
      WTSDown,
      WTSInit
    }

    static void Main(string[] args)
    {
      ListUsers(Environment.MachineName);
    }

    public static void ListUsers(string serverName)
    {
      IntPtr serverHandle = IntPtr.Zero;
      List<string> resultList = new List<string>();
      serverHandle = WTSOpenServer(serverName);

      try
      {
        IntPtr sessionInfoPtr = IntPtr.Zero;
        IntPtr userPtr = IntPtr.Zero;
        IntPtr domainPtr = IntPtr.Zero;
        Int32 sessionCount = 0;
        Int32 retVal = WTSEnumerateSessions(serverHandle, 0, 1, ref sessionInfoPtr, ref sessionCount);
        Int32 dataSize = Marshal.SizeOf(typeof(WTS_SESSION_INFO));
        IntPtr currentSession = sessionInfoPtr;
        uint bytes = 0;

        if (retVal != 0)
        {
          for (int i = 0; i < sessionCount; i++)
          {
            WTS_SESSION_INFO si = (WTS_SESSION_INFO)Marshal.PtrToStructure((System.IntPtr)currentSession, typeof(WTS_SESSION_INFO));
            currentSession += dataSize;

            WTSQuerySessionInformation(serverHandle, si.SessionID, WTS_INFO_CLASS.WTSUserName, out userPtr, out bytes);
            WTSQuerySessionInformation(serverHandle, si.SessionID, WTS_INFO_CLASS.WTSDomainName, out domainPtr, out bytes);

            Console.WriteLine("Domain and User: " + Marshal.PtrToStringAnsi(domainPtr) + "\\" + Marshal.PtrToStringAnsi(userPtr));

            WTSFreeMemory(userPtr); 
            WTSFreeMemory(domainPtr);
          }

          WTSFreeMemory(sessionInfoPtr);
        }
      }
      finally
      {
        WTSCloseServer(serverHandle);
      }

    }

  }
}

using System;
using System.Security.Principal;
using Cassia;

namespace CassiaSample
{
    public static class Program
    {
        public static void Main(string[] args)
        {
            ITerminalServicesManager manager = new TerminalServicesManager();
            using (ITerminalServer server = manager.GetRemoteServer("your-server-name"))
            {
                server.Open();
                foreach (ITerminalServicesSession session in server.GetSessions())
                {
                    NTAccount account = session.UserAccount;
                    if (account != null)
                    {
                        Console.WriteLine(account);
                    }
                }
            }
        }
    }
}