C# 中獲取主機的DNS域名（練習單線程，多線程，線程池）

2.運行效果如下：

3.核心源代碼：

Form1.cs中的源碼（設計源碼省略，由於單線程，多線程，線程池只有部分源碼不同，將其合到一處）

1. using System;
2. using System.Collections.Generic;
3. using System.ComponentModel;
4. using System.Data;
5. using System.Drawing;
6. using System.Linq;
7. using System.Text;
8. using System.Windows.Forms;
9. using System.Net;
10. using System.Threading;
11. namespace ScanComputer
12. {
13. public partial class Form1 : Form
14. {
15. public string start;//記錄當前IP字符串
16. public int n;//計數
17. public DateTime dt1;//當前時間
18. public Form1()
19. {
20. InitializeComponent();
21. }
22. private void button1_Click(object sender, EventArgs e)
23. {
24. groupBox1.Enabled = false;
25. button1.Enabled = false;
26. listBox1.Items.Clear();
27. int ipCount =n= (int)numericUpDown5.Value - (int)numericUpDown4.Value + 1;//計算總IP數量
28. // 多線程
29. //Thread[] scanthreads = new Thread[ipCount];
30. //for (int i = 0; i < ipCount; i++)
31. //{
32. // start = numericUpDown1.Value + "." + numericUpDown2.Value + "." + numericUpDown3.Value + "." + (numericUpDown4.Value+i);
33. // scan sc = new scan(this);
34. // sc.ip = start;
35. // scanthreads[i] = new Thread(sc.CheckComputer);
36. // scanthreads[i].Name = i.ToString();
37. // scanthreads[i].Start();
38. //}
39. //線成池
40. //scan[] sc = new scan[ipCount];
41. //dt1 = DateTime.Now;//記下當前時間
42. //for (int i = 0; i < ipCount; i++)
43. //{
44. // start = numericUpDown1.Value + "." + numericUpDown2.Value + "." + numericUpDown3.Value + "." + (numericUpDown4.Value + i);
45. // sc[i] = new scan(this);
46. // sc[i].ip = start;
47. // //ThreadPool.QueueUserWorkItem(new WaitCallback(sc[i].CheckComputer));
48. //}
49. //單線程
50. scan sc = new scan(this);
51. dt1 = DateTime.Now;//記下當前時間
52. for (int i = 0; i < ipCount; i++)
53. {
54. start = numericUpDown1.Value + "." + numericUpDown2.Value + "." + numericUpDown3.Value + "." + (numericUpDown4.Value + i);
55. sc.ip = start;
56. object o = null;
57. sc.CheckComputer(o);
58. }
59. }
60. public delegate void GetComputerDnsDelegate(string strIP, string strHostName);//在一個線程中訪問另一個線程（此處為main線程）的控件要使用委托
61. public void addInfotoListbox(string strIP,string hostName)
62. {
63. if (listBox1.InvokeRequired)
64. {
65. GetComputerDnsDelegate get = addInfotoListbox;
66. listBox1.Invoke(get, strIP, hostName);
67. }
68. else
69. {
70. n--;
71. this.listBox1.Items.Add("IP地址----" + strIP + ",Dns域名---" + hostName+" ");
72. if (n == 0)//若n=0說明所有線程已經完成任務，輸出總時間
73. {
74. DateTime dt2 = DateTime.Now;
75. TimeSpan ts = dt2 - dt1;
76. string str=string.Format("總共用了{0:0.00}毫秒" , ts.TotalMilliseconds);//精確到0.00毫秒
77. this.listBox1.Items.Add(str);
78. this.groupBox1.Enabled = true;
79. button1.Enabled = true;
80. }
81. }
82. }
83. }
84. }

scan.cs源代碼

1. using System;
2. using System.Collections.Generic;
3. using System.Linq;
4. using System.Text;
5. using System.Net;
6. using System.Windows.Forms;
7. using System.Threading;
8. namespace ScanComputer
9. {
10. class scan
11. {
12. Form1 form;
13. public string ip;
14. IPAddress IP;
15. public scan(Form1 form)
16. {
17. this.form = form;
18. }
19. public void CheckComputer(object obj)
20. {
21. try
22. {
23. IP = IPAddress.Parse(ip);
24. }
25. catch
26. {
27. MessageBox.Show("不合法的IP地址！");
28. }
29. try
30. {
31. string hostname = Dns.GetHostEntry(IP).HostName;
32. form.addInfotoListbox(ip, hostname);
33. }
34. catch
35. {
36. return;
37. }
38. }
39. }
40. }