Retrieving network computer names c#

Recently someone told me, he couldn't get the name of the computers on the network! so I tried to create and used some .net libraries but i couldn't get the name of the computer either. 

I'm only getting the I.P. address of computers on the certain network, so I look for some articles that could help me out! and found this micorosft's documentation click here

As you can see I only have two computers here! it works out for me! I hope this sample helps someone out !!!!

Sample Code

clsComputerNetworks.cs

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

namespace getComputerNetworkNames
{
    /// 

    /// for micorosoft's documentation
    /// http://msdn.microsoft.com/en-us/library/aa370623(VS.85).aspx
    /// another helpful site
    /// http://www.pinvoke.net/default.aspx/netapi32.netserverenum
    /// http://win32.mvps.org/index.html
    /// when i searched in google i found this good article at codeproject
    /// http://www.codeproject.com/KB/IP/ListNetworkComputers.aspx 
    /// 
    public class clsComputerNetworks
    {
        #region constants

        public const uint ERROR_SUCCESS        = 0;
        public const uint ERROR_MORE_DATA    = 234;
        public enum SV_101_TYPES:uint
        {
            SV_TYPE_WORKSTATION= 0x00000001,
            SV_TYPE_SERVER= 0x00000002,
            SV_TYPE_SQLSERVER = 0x00000004,
            SV_TYPE_DOMAIN_CTRL= 0x00000008,
            SV_TYPE_DOMAIN_BAKCTRL= 0x00000010,
            SV_TYPE_TIME_SOURCE= 0x00000020,
            SV_TYPE_AFP= 0x00000040,
            SV_TYPE_NOVELL= 0x00000080,
            SV_TYPE_DOMAIN_MEMBER = 0x00000100,
            SV_TYPE_PRINTQ_SERVER = 0x00000200,
            SV_TYPE_DIALIN_SERVER = 0x00000400,
            SV_TYPE_XENIX_SERVER = 0x00000800,
            SV_TYPE_SERVER_UNIX = 0x00000800,
            SV_TYPE_NT = 0x00001000,
            SV_TYPE_WFW = 0x00002000,
            SV_TYPE_SERVER_MFPN= 0x00004000,
            SV_TYPE_SERVER_NT = 0x00008000,
            SV_TYPE_POTENTIAL_BROWSER = 0x00010000,
            SV_TYPE_BACKUP_BROWSER= 0x00020000,
            SV_TYPE_MASTER_BROWSER= 0x00040000,
            SV_TYPE_DOMAIN_MASTER = 0x00080000,
            SV_TYPE_SERVER_OSF= 0x00100000,
            SV_TYPE_SERVER_VMS= 0x00200000,
            SV_TYPE_WINDOWS= 0x00400000, 
            SV_TYPE_DFS= 0x00800000, 
            SV_TYPE_CLUSTER_NT= 0x01000000, 
            SV_TYPE_TERMINALSERVER= 0x02000000, 
            SV_TYPE_CLUSTER_VS_NT = 0x04000000, 
            SV_TYPE_DCE= 0x10000000, 
            SV_TYPE_ALTERNATE_XPORT= 0x20000000, 
            SV_TYPE_LOCAL_LIST_ONLY= 0x40000000, 
            SV_TYPE_DOMAIN_ENUM= 0x80000000,
            SV_TYPE_ALL= 0xFFFFFFFF 
        };

        #endregion 
        
        [StructLayout(LayoutKind.Sequential)]
        public struct _SERVER_INFO_100
        {
            internal int sv100_platform_id;
            [MarshalAs(UnmanagedType.LPWStr)]
            internal string sv100_name;
        }

        [DllImport("netapi32.dll", CharSet = CharSet.Auto, EntryPoint = "NetServerEnum", SetLastError = true)]
        public static extern int NetServerEnum([MarshalAs(UnmanagedType.LPWStr)]string servername,
        int level,
        out IntPtr bufptr,
        int prefmaxlen,
        ref int entriesread,
        ref int totalentries,
        SV_101_TYPES servertype,
        [MarshalAs(UnmanagedType.LPWStr)]string domain,
        IntPtr resume_handle);

        [DllImport("netapi32.dll", EntryPoint = "NetApiBufferFree")]
        public static extern int NetApiBufferFree(IntPtr buffer);

        private static IntPtr bufferRecData = IntPtr.Zero;
        private static IntPtr Buffer_ = IntPtr.Zero;
        private static int entriesEnumerated = 0;
        private static int totalComputersInNetwork = 0;
        private static IntPtr resHandle = IntPtr.Zero;
        private static int sizeofINFO = Marshal.SizeOf(typeof(_SERVER_INFO_100));

        public static List<string> getNetworkComputers()
        {
            List<string> networkComputers = new List<string>();

            try
            {
                int ret = NetServerEnum(null, 100, out bufferRecData,
                    -1,
                    ref entriesEnumerated,
                    ref totalComputersInNetwork, 
                    SV_101_TYPES.SV_TYPE_WORKSTATION | SV_101_TYPES.SV_TYPE_SERVER, 
                    null,  
                    resHandle);

                if (ret == 0)
                {
                    for (int intCounter = 0; intCounter < totalComputersInNetwork; intCounter++)
                    {
                       Buffer_ = new IntPtr((int)bufferRecData +
                                   (intCounter * sizeofINFO));
                   
                        _SERVER_INFO_100 svrInfo = (_SERVER_INFO_100)
                            Marshal.PtrToStructure(Buffer_,
                                    typeof(_SERVER_INFO_100));


                        networkComputers.Add(svrInfo.sv100_name);
                    }
                }
            }
            catch (Exception ex)
            {
                throw;
            }
            finally
            {
                NetApiBufferFree(bufferRecData);
            }

            return networkComputers;
        }
    }
}

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;

namespace getComputerNetworkNames
{
    public partial class frmComputerName : Form
    {
        public frmComputerName()
        {
            InitializeComponent();
        }


        private void btnGetComputerName_Click(object sender, EventArgs e)
        {
            try
            {
                if (this.lstComputerName.Items.Count > 0)
                    this.lstComputerName.Items.Clear();

                
                List ComputerName = clsComputerNetworks.getNetworkComputers();

                foreach (string name in ComputerName)
                {
                    this.lstComputerName .Items.Add(name);
                }

            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }

        }
    }
}