c# how to determine session id of specific logged in windows user

Question

like the title said, i want to create a method to search a windows user session id by the domainname\username.

I already finished to read the currently logged in users, but id do not know to determine their session id.

My goal is to kill the session of specific users.

Possible duplicate of [Log off a Windows user locally using c#](http://stackoverflow.com/questions/14466373/log-off-a-windows-user-locally-using-c-sharp) — , Sep 28 '16 at 15:02

score 1 · Answer 1 · edited May 23 '17 at 10:29

Based on the code from: How do you retrieve a list of logged-in/connected users in .NET?

Modified a bit, the following code will list the logged in users and their corresponding session ids.

class Program
{
    static void Main(string[] args)
    {
        var userLogins = new UserLogins();

        // this code gets the users from localhost -
        // can change this to a remote hostname on the network
        var users = UserLogins.GetUsers("localhost");

        foreach (var user in users)
        {
            Console.WriteLine("User: " + user);
        }

        Console.ReadKey();

    }

    public class UserLogins
    {

        [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(
            System.IntPtr hServer, int sessionId, WTS_INFO_CLASS wtsInfoClass, out System.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
        }

        public static IntPtr OpenServer(String Name)
        {
            IntPtr server = WTSOpenServer(Name);
            return server;
        }
        public static void CloseServer(IntPtr ServerHandle)
        {
            WTSCloseServer(ServerHandle);
        }
        public static IEnumerable<UserInfo> GetUsers(String ServerName)
        {
            IntPtr serverHandle = IntPtr.Zero;
            List<String> resultList = new List<string>();
            serverHandle = OpenServer(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));
                Int32 currentSession = (int)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);

                        yield return new UserInfo
                        {
                            Domain = Marshal.PtrToStringAnsi(domainPtr),
                            User = Marshal.PtrToStringAnsi(userPtr),
                            SessionID = si.SessionID
                        };

                        WTSFreeMemory(userPtr);
                        WTSFreeMemory(domainPtr);
                    }

                    WTSFreeMemory(SessionInfoPtr);
                }
            }
            finally
            {
                CloseServer(serverHandle);
            }
        }
    }
    public class UserInfo
    {
        public string Domain { get; set; }
        public string User { get; set; }

        public int SessionID { get; set; }

        public override string ToString()
        {
            return string.Format("{0}\\{1}: {2}", Domain, User, SessionID);
        }
    }
}

I tried this code, but i ended up how to access the users session id. Is all the informations stored in "user" here: Console.WriteLine("User: " + user); So the "user" has also stored the session id?? — , Sep 29 '16 at 11:40
Ok i figured out myself. But now if i run my application on a server and connect via remote, its says no user is logged in. — , Sep 29 '16 at 12:17

score 0 · Answer 2 · answered Sep 28 '16 at 15:13

0

create a commandline application. call the command "query session" and store the results in a list for example sessionList. than you can say:

var sessionList = Process.Start("cmd", "c:\>query session").ToList();
sessionList = sessionList.Where(x => x.Username == "Piet")
foreach( var item in sessionList)
{
 console.WriteLine(item.id)
}

maybe you need to finetune it a little bit but it will work

answered Sep 28 '16 at 15:13

there is no method .toList() for Process.Start Can you please tell me how am i able to send the output to a list? – Sep 29 '16 at 11:36
if i run the process cmd query session i do not have the table which contains the user informations in the output stream. if i run query session manually from the command promt i get the information about my user. – Sep 29 '16 at 14:11

c# how to determine session id of specific logged in windows user

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