C#利用广播实现群发功能

C#利用广播实现群发功能

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1. using System;  
2. using System.Collections.Generic;  
3. using System.ComponentModel;  
4. using System.Data;  
5. using System.Drawing;  
6. using System.Text;  
7. using System.Windows.Forms;  
8. //添加的命名空间引用  
9. using System.Net;  
10. using System.Net.Sockets;  
11. using System.Threading;  
12. namespace BroadcastExample  
13. {  
14.     public partial class FormBroacast : Form  
15.     {  
16.         delegate void AppendStringCallback(string text);  
17.         AppendStringCallback appendStringCallback;  
18.         //使用的接收端口号  
19.         private int port = 8001;  
20.         private UdpClient udpClient;  
21.         public FormBroacast()  
22.         {  
23.             InitializeComponent();  
24.             appendStringCallback = new AppendStringCallback(AppendString);  
25.         }  
26.   
27.         private void FormBroacast_Load(object sender, EventArgs e)  
28.         {  
29.             Thread myThread = new Thread(ReceiveData);  
30.             //将线程设为后台运行  
31.             myThread.IsBackground = true;  
32.             myThread.Start();  
33.         }  
34.   
35.         
36.         /// <summary>  
37.         /// 在后台运行的接收线程  
38.         /// </summary>  
39.         private void ReceiveData()  
40.         {  
41.             //在本机指定的端口接收  
42.             udpClient = new UdpClient(port);  
43.             IPEndPoint remote = null;  
44.             //接收从远程主机发送过来的信息；  
45.             while (true)  
46.             {  
47.                 try  
48.                 {  
49.                     //关闭udpClient时此句会产生异常  
50.                     byte[] bytes = udpClient.Receive(ref remote);  
51.                     string str = Encoding.UTF8.GetString(bytes, 0, bytes.Length);  
52.                     AppendString(string.Format("来自{0}：{1}", remote, str));  
53.                 }  
54.                 catch  
55.                 {  
56.                     //退出循环，结束线程  
57.                     break;  
58.                 }  
59.             }  
60.         }  
61.   
62.         /// <summary>  
63.         /// 发送消息  
64.         /// </summary>  
65.         /// <param name="sender"></param>  
66.         /// <param name="e"></param>  
67.         private void buttonSend_Click(object sender, EventArgs e)  
68.         {  
69.             UdpClient myUdpClient = new UdpClient();  
70.             try  
71.             {  
72.                 //让其自动提供子网中的IP广播地址  
73.                 IPEndPoint iep = new IPEndPoint(IPAddress.Broadcast, 8001);  
74.                 //将发送内容转换为字节数组  
75.                 byte[] bytes =Encoding.UTF8.GetBytes(textBox1.Text);  
76.                 //向子网发送信息  
77.                 myUdpClient.Send(bytes, bytes.Length, iep);  
78.                 textBox1.Clear();  
79.                 textBox1.Focus();  
80.             }  
81.             catch (Exception err)  
82.             {  
83.                 MessageBox.Show(err.Message, "发送失败");  
84.             }  
85.             finally  
86.             {  
87.                 myUdpClient.Close();  
88.             }  
89.         }  
90.          
91.         private void FormBroacast_FormClosing(object sender, FormClosingEventArgs e)  
92.         {  
93.             udpClient.Close();  
94.         }  
95.   
96.         private void AppendString(string text)  
97.         {  
98.             if (richTextBox1.InvokeRequired == true)  
99.             {  
100.                 this.Invoke(appendStringCallback, text);  
101.             }  
102.             else  
103.             {  
104.                 richTextBox1.AppendText(text + "\r\n");  
105.             }  
106.         }  
107.     }  
108. }  

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