01.using System;
02.using System.Drawing;
03.using System.Net;
04.using System.Text;
05.using System.Windows.Forms;
06.class AsyncResolve Form:
07.{
08. TextBox address;
09. ListBox results;
10. private AsyncCallback OnResolved;
11. public AsyncResolve()
12. {
13. Text = "DNS Address Resolver";
14. Size = new Size(400,380);
15. OnResolved = new AsyncCallback(Resolved);
16. Label label1 = new Label();
17. label1.Parent = this;
18. label1.Text = "Enter address to resolve:";
19. label1.AutoSize = true;
20. label1.Location = new Point(10, 10);
21. address = new TextBox();
22. address.Parent = this;
23. address.Size = new Size(200, 2 * Font.Height);
24. address.Location = new Point(10, 35);
25. results = new ListBox();
26. results.Parent = this;
27. results.Location = new Point(10, 65);
28. results.Size = new Size(350, 20 * Font.Height);
29. Button checkit = new Button();
30. checkit.Parent = this;
31. checkit.Text = "Resolve";
32. checkit.Location = new Point(235,32);
33. checkit.Size = new Size(7 * Font.Height, 2 * Font.Height);
34. checkit.Click += new EventHandler(ButtonResolveOnClick);
35. }
36. void ButtonResolveOnClick(object obj, EventArgs ea)
37. {
38. results.Items.Clear();
39. string addr = address.Text;
40. Object state = new Object();
41. Dns.BeginResolve(addr, OnResolved, state);
42. }
43. private void Resolved(IAsyncResult ar)
44. {
45. string buffer;
46. IPHostEntry iphe = Dns.EndResolve(ar);
47. buffer = "Host name: " + iphe.HostName;
48. results.Items.Add(buffer);
49. foreach(string alias in iphe.Aliases)
50. {
51. buffer = "Alias: " + alias;
52. results.Items.Add(buffer);
53. }
54. foreach(IPAddress addrs in iphe.AddressList)
55. {
56. buffer = "Address: " + addrs.ToString();
57. results.Items.Add(buffer);
58. }
59. }
60. public static void Main()
61. {
62. Application.Run(new AsyncResolve());
63. }
64.}
