Get List of computers connected in LAN

using System.Net.NetworkInformation;

List<string> IP = new List<string>();

private void button1_Click(object sender, EventArgs e)

{

   Ping obj = new Ping();

   for (int i = 0; i < 255; i++)

   {

     try

     {

      PingReply objreply = obj.Send("192.168.0." + i.ToString());

      if (objreply.Status != IPStatus.DestinationHostUnreachable)

       {

          IP.Add(objreply.Address.ToString());

          IP.Add(Dns.GetHostByAddress(objreply.Address).HostName);

       }

     }

     catch

     {

     }

   }           

   ListBox.DataSource = IP;

}