C# Signature:

        [DllImport("netapi32.dll", SetLastError=true)]
        private static extern int NetSessionEnum(
            [In,MarshalAs(UnmanagedType.LPWStr)] string ServerName,
            [In,MarshalAs(UnmanagedType.LPWStr)] string UncClientName,
            [In,MarshalAs(UnmanagedType.LPWStr)] string UserName,
            Int32 Level,
            out IntPtr bufptr,
            int prefmaxlen,
            ref Int32 entriesread,
            ref Int32 totalentries,
            ref Int32 resume_handle);

VB Signature:

Declare Function NetSessionEnum Lib "netapi32.dll" (TODO) As TODO

User-Defined Types:

[ StructLayout( LayoutKind.Sequential )]public struct SESSION_INFO_

    {
        /// <summary>
        /// Unicode string specifying the name of the computer that established the session.
        /// </summary>
        [MarshalAs(UnmanagedType.LPWStr)]public string sesi502_cname;
        /// <summary>
        /// <value>Unicode string specifying the name of the user who established the session.</value>
        /// </summary>
        [MarshalAs(UnmanagedType.LPWStr)]public string sesi502_username;
        /// <summary>
        /// <value>Specifies the number of files, devices, and pipes opened during the session.</value>
        /// </summary>
        public uint sesi502_num_opens;
        /// <summary>
        /// <value>Specifies the number of seconds the session has been active. </value>
        /// </summary>
        public uint sesi502_time;
        /// <summary>
        /// <value>Specifies the number of seconds the session has been idle.</value>
        /// </summary>
        public uint sesi502_idle_time;
        /// <summary>
        /// <value>Specifies a value that describes how the user established the session.</value>
        /// </summary>
        public uint sesi502_user_flags;
        /// <summary>
        /// <value>Unicode string that specifies the type of client that established the session.</value>
        /// </summary>
        [MarshalAs(UnmanagedType.LPWStr)]public string sesi502_cltype_name;
        /// <summary>
        /// <value>Specifies the name of the transport that the client is using to communicate with the server.</value>
        /// </summary>
        [MarshalAs(UnmanagedType.LPWStr)]public string sesi502_transport;

    }

public enum NERR

    {
        /// <summary>
        /// Operation was a success.
        /// </summary>
        NERR_Success = 0,
        /// <summary>
        /// More data available to read. dderror getting all data.
        /// </summary>
        ERROR_MORE_DATA = 234,
        /// <summary>
        /// Network browsers not available.
        /// </summary>
        ERROR_NO_BROWSER_SERVERS_FOUND = 6118,
        /// <summary>
        /// LEVEL specified is not valid for this call.
        /// </summary>
        ERROR_INVALID_LEVEL = 124,
        /// <summary>
        /// Security context does not have permission to make this call.
        /// </summary>
        ERROR_ACCESS_DENIED = 5,
        /// <summary>
        /// Parameter was incorrect.
        /// </summary>
        ERROR_INVALID_PARAMETER = 87,
        /// <summary>
        /// Out of memory.
        /// </summary>
        ERROR_NOT_ENOUGH_MEMORY = 8,
        /// <summary>
        /// Unable to contact resource. Connection timed out.
        /// </summary>
        ERROR_NETWORK_BUSY = 54,
        /// <summary>
        /// Network Path not found.
        /// </summary>
        ERROR_BAD_NETPATH = 53,
        /// <summary>
        /// No available network connection to make call.
        /// </summary>
        ERROR_NO_NETWORK = 1222,
        /// <summary>
        /// Pointer is not valid.
        /// </summary>
        ERROR_INVALID_HANDLE_STATE = 1609,
        /// <summary>
        /// Extended Error.
        /// </summary>
        ERROR_EXTENDED_ERROR= 1208,
        /// <summary>
        /// Base.
        /// </summary>
        NERR_BASE = 2100,
        /// <summary>
        /// Unknown Directory.
        /// </summary>
        NERR_UnknownDevDir = (NERR_BASE + 16),
        /// <summary>
        /// Duplicate Share already exists on server.
        /// </summary>
        NERR_DuplicateShare = (NERR_BASE + 18),
        /// <summary>
        /// Memory allocation was to small.
        /// </summary>
        NERR_BufTooSmall = (NERR_BASE + 23)
    }

Alternative Managed API:

Do you know one? Please contribute it!

Notes:

None.

Tips & Tricks:

Please add some!

Sample Code:

        /// <summary>
        /// Returns all SESSIONS of the specified server. Returns an array of SESSION_INFO_502 structures.
        /// </summary>
        /// <param name="server">Server to get shares for without preceding backslashes.</param>
        /// <returns>SESSION_INFO_502 STRUCTURE ARRAY</returns>
        public static SESSION_INFO_502[] EnumSessions(string server)
        {
            IntPtr BufPtr;
            int res = 0;
            Int32 er=0,tr=0,resume=0;
            BufPtr = (IntPtr)Marshal.SizeOf(typeof(SESSION_INFO_502));
            SESSION_INFO_502[] results = new SESSION_INFO_502[0];
            do
            {
                res = NetSessionEnum(server,null,null,502,out BufPtr,-1,ref er,ref tr,ref resume);
                results = new SESSION_INFO_502[er];
                if (res == (int)NERR.ERROR_MORE_DATA || res == (int)NERR.NERR_Success)
                {
                    Int32 p = BufPtr.ToInt32();
                    for (int i = 0;i <er;i++)
                    {

                        SESSION_INFO_502 si = (SESSION_INFO_502)Marshal.PtrToStructure(new IntPtr(p),typeof(SESSION_INFO_502));
                        results[i] = si;
                        p += Marshal.SizeOf(typeof(SESSION_INFO_502));
                    }
                }
                Marshal.FreeHGlobal(BufPtr);
            }
            while (res==(int)NERR.ERROR_MORE_DATA);
            return results;
        }