DNS Address Resolver
using System;
using System.Drawing;
using System.Net;
using System.Text;
using System.Windows.Forms;
public class AsyncResolve: Form {
TextBox address;
ListBox results;
private AsyncCallback OnResolved;
public AsyncResolve()
{
Text = "DNS Address Resolver";
Size = new Size(400,380);
OnResolved = new AsyncCallback(Resolved);
Label label1 = new Label();
label1.Parent = this;
label1.Text = "Enter address to resolve:";
label1.AutoSize = true;
label1.Location = new Point(10, 10);
address = new TextBox();
address.Parent = this;
address.Size = new Size(200, 2 * Font.Height);
address.Location = new Point(10, 35);
results = new ListBox();
results.Parent = this;
results.Location = new Point(10, 65);
results.Size = new Size(350, 20 * Font.Height);
Button checkit = new Button();
checkit.Parent = this;
checkit.Text = "Resolve";
checkit.Location = new Point(235,32);
checkit.Size = new Size(7 * Font.Height, 2 * Font.Height);
checkit.Click += new EventHandler(ButtonResolveOnClick);
}
void ButtonResolveOnClick(object obj, EventArgs ea)
{
results.Items.Clear();
string addr = address.Text;
Object state = new Object();
Dns.BeginResolve(addr, OnResolved, state);
}
private void Resolved(IAsyncResult ar)
{
string buffer;
IPHostEntry iphe = Dns.EndResolve(ar);
buffer = "Host name: " + iphe.HostName;
results.Items.Add(buffer);
foreach(string alias in iphe.Aliases)
{
buffer = "Alias: " + alias;
results.Items.Add(buffer);
}
foreach(IPAddress addrs in iphe.AddressList)
{
buffer = "Address: " + addrs.ToString();
results.Items.Add(buffer);
}
}
public static void Main()
{
Application.Run(new AsyncResolve());
}
}
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