C# Determine remote desktop login user's computer name

Question

I have been researching for a couple of weeks now, on and off, on how to determine the computer name of the user that is logged in via remote desktop.

I have an application that users run on a terminal server environment, and I would like to capture and store the name of the computer that they are using to connect to the terminal server with.

So far, I have not been able to find code or create my own that can do this, and I think I am just not asking the right questions.

Any assistance would be greatly appreciated.

PS. I am using C# and .Net 4.0

Bahaism

Answer 1

Okay so I have found a solution at http://www.amasso.info/?p=165

Code reproduced below...

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Security.Principal;
using System.Net;

namespace loginName
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            WindowsPrincipal wp = new WindowsPrincipal(WindowsIdentity.GetCurrent());
            MessageBox.Show(wp.Identity.Name); // Username
            MessageBox.Show(GetTerminalServerClientNameWTSAPI()); // Remote Host PC Name

        }

        private static string GetTerminalServerClientNameWTSAPI()
        {

            const int WTS_CURRENT_SERVER_HANDLE = -1;

            IntPtr buffer = IntPtr.Zero;
            uint bytesReturned;

            string strReturnValue = "";
            try
            {
                WTSQuerySessionInformation(IntPtr.Zero, WTS_CURRENT_SERVER_HANDLE, WTS_INFO_CLASS.WTSClientName, out buffer, out bytesReturned);
                strReturnValue = System.Runtime.InteropServices.Marshal.PtrToStringAnsi(buffer);
            }

            finally
            {
                buffer = IntPtr.Zero;
            }

            return strReturnValue;
        }

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

        }

        [System.Runtime.InteropServices.DllImport("Wtsapi32.dll")]
        private static extern bool WTSQuerySessionInformation(System.IntPtr hServer, int sessionId, WTS_INFO_CLASS wtsInfoClass, out System.IntPtr ppBuffer, out uint pBytesReturned);

    }
}

Bahaism

WTS_CURRENT_SERVER_HANDLE is 0, not -1. And it should be specified as first argument only. Second argument can be WTS_CURRENT_SESSION - which is -1, not 0. – Bartonbartosch

Answer 2

I know this is an old post, but this is what I use and it'll work on Win 2000 thru Server 2019. I have not confirmed Server 2022 yet, but it should also be OK:

System.Environment.GetEnvironmentVariable("ClientName") It returns a string of the client name that's connected. Works for TS & XenApp.

Hope it'll save others time. The accepted answer is overkill.

Roose

Thanks I did not know this. Overkill is underrated. – Bahaism

Answer 3

See this question. The Cassia library is another option if you'd like to avoid the P/Invokes or get additional information about the session.

Tolerant

I did see that link around the same time I posted my query. Thanks – Bahaism