Quering IP Address

using System.Windows.Forms;
using System.Net; //Added
using System.Net.Sockets; //Added



namespace Quering_IPAddresses
{
    public partial class Form1 : Form
    {
        /// <summary>
        /// Using the System.Net namespace
        /// Looking at the Dns class.
        /// </summary>
        public Form1()
        {
            InitializeComponent();
        }

        private void btnGetLocalIPAddress_Click(object sender, EventArgs e)
        {
            ///Use Dns class defined in System.Net namespace
            ///Use the GetHostName method to get the name of this (local) computer
            string hostname = Dns.GetHostName();

            //Get this (local) host IPAddress
            //You can use the method (defined in the Dns class):

            ///public static IPAddress[] GetHostAddresses(string hostNameOrAddress)
            IPAddress[] ipaddresses = Dns.GetHostAddresses(hostname);
         
            //display the local host name
            richTextBox1.Text = "local hostname :  " + hostname + "\n\n";
         
            //display its ipaddresses
            foreach (IPAddress address in ipaddresses)
            {
                richTextBox1.AppendText(address + "\n");
            }
        }

        private void btnIPAddressesOfHostname_Click(object sender, EventArgs e)
        {
            richTextBox1.Clear();
            try
            {
                //get hostname from user
                string hostname = txtHostName.Text;

                //display its ip addresses
                IPAddress[] ipaddresses = Dns.GetHostAddresses(hostname);

                //display its ipaddresses
                foreach (IPAddress address in ipaddresses)
                {
                    richTextBox1.AppendText(address + "\n");
                }
            }
            catch (ArgumentException ae)
            {
                MessageBox.Show(ae.Message);
            }
            catch (SocketException se)
            {
                MessageBox.Show(se.Message);
            }
        }

        private void btnDownLoadPage_Click(object sender, EventArgs e)
        {
            try
            {
                ///Use the WebClient class defined in the System.Net namespace
                ///The WebClient defines a method: DownloadString

                ///Create a WebClient object
                WebClient client = new WebClient();
                ///Use the DownLoadString method and pass it the address
                string result = client.DownloadString(txtAddress.Text);

                //display
                richTextBox2.Text = result;
            }
            catch (WebException we)
            {
                //catch this exception in case there was an error while downloading
                MessageBox.Show(we.Message);
            }
        }
    }
}