C#用UDP异步发送信息

超、凢脫俗 2022-09-18 15:57 161阅读 0赞

C\#用UDP异步发送信息

**\[csharp\]**  [view plain][] [copy][view plain]

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.    
9.  //添加的命名空间引用  
10. **using** System.Net;  
11. **using** System.Net.Sockets;  
12. **using** System.Threading;  
13.   
14. **namespace** AsyncUdpChatExample  
15. \{  
16.     **public** partial **class** FormAsyncChat : Form  
17.     \{  
18.           
19.         AddListBoxItemCallback listBoxCallback;  
20.         //使用的接收端口号  
21.         **private** **int** port = 8001;  
22.         //接收信息用UdpClient实例  
23.         UdpClient receiveClient;  
24.         IPEndPoint iep;  
25.         String sendMessage;  
26.         **public** FormAsyncChat()  
27.         \{  
28.             InitializeComponent();  
29.             listBoxCallback = **new** AddListBoxItemCallback(AddListBoxItem);  
30.         \}  
31.   
32.         /// <summary>  
33.         /// 初始化窗体  
34.         /// </summary>  
35.         /// <param name="sender"></param>  
36.         /// <param name="e"></param>  
37.         **private** **void** FormChat\_Load(**object** sender, EventArgs e)  
38.         \{  
39.             //设置listBox样式  
40.             listBoxReceive.HorizontalScrollbar = **true**;  
41.             listBoxReceive.Dock = DockStyle.Fill;  
42.             //获取本机第一个可用IP地址  
43.             IPAddress myIP = (IPAddress)Dns.GetHostAddresses(Dns.GetHostName()).GetValue(1);  
44.             //为了在同一台机器调试，此IP也作为默认远程IP  
45.             textBoxRemoteIP.Text = myIP.ToString();  
46.             receiveClient = **new** UdpClient(port);  
47.   
48.             //创建一个线程接收远程主机发来的信息  
49.             Thread myThread = **new** Thread(ReceiveData);  
50.             //将线程设为后台运行  
51.             myThread.IsBackground = **true**;  
52.             myThread.Start();  
53.             textBoxSend.Focus();  
54.         \}  
55.           
56.         /// <summary>  
57.         /// 在后台运行的接收线程  
58.         /// </summary>  
59.         **private** **void** ReceiveData()  
60.         \{  
61.             //在本机指定的端口接收  
62.             UdpState udpState = **new** UdpState();  
63.             udpState.IpEndPoint = **null**;  
64.             udpState.MyudpClient = receiveClient;  
65.             //接收从远程主机发送过来的信息；  
66.             IAsyncResult ar =  udpState.MyudpClient.BeginReceive(ReceiveUdpClientCallback, udpState);  
67.             ar.AsyncWaitHandle.WaitOne();  
68.             Console.Write("线程结束");  
69.         \}  
70.   
71.         /// <summary>  
72.         /// 接收信息回调方法  
73.         /// </summary>  
74.         /// <param name="ar"></param>  
75.         **void** ReceiveUdpClientCallback(IAsyncResult ar)  
76.         \{  
77.             **try**  
78.             \{  
79.                 UdpClient u = (UdpClient)((UdpState)(ar.AsyncState)).MyudpClient;  
80.                 IPEndPoint remote = (IPEndPoint)((UdpState)(ar.AsyncState)).IpEndPoint;  
81.                 Byte\[\] receiveBytes = u.EndReceive(ar, **ref** remote);  
82.                 **string** str = Encoding.UTF8.GetString(receiveBytes, 0, receiveBytes.Length);  
83.                 AddItem(listBoxReceive, **string**.Format("来自\{0\}：\{1\}", remote, str));  
84.                 ReceiveData();//继续接受数据  
85.             \}  
86.             **catch** (Exception ex)  
87.             \{  
88.                 AddItem(listBoxReceive, **string**.Format("错误信息\{0\}", ex.ToString()));  
89.             \}  
90.         \}  
91.         /// <summary>  
92.         /// 发送数据到远程主机  
93.         /// </summary>  
94.         **private** **void** sendData()  
95.         \{  
96.             UdpClient sendUdpClient = **new** UdpClient();  
97.             IPAddress remoteIP;  
98.             **if** (IPAddress.TryParse(textBoxRemoteIP.Text, **out** remoteIP) == **false**)  
99.             \{  
100.                 MessageBox.Show("远程IP格式不正确");  
101.                 **return**;  
102.             \}  
103.             iep = **new** IPEndPoint(remoteIP, port);  
104.             sendMessage = textBoxSend.Text;  
105.             **byte**\[\] bytes = System.Text.Encoding.UTF8.GetBytes(sendMessage);  
106.             **try**  
107.             \{  
108.                 //异步发送数据  
109.                 IAsyncResult ar=  
110.                 sendUdpClient.BeginSend(bytes, bytes.Length, iep, SendCallback, sendUdpClient);//sendUdpClient是传给回调函数SendCallback的参数  
111.                   
112.                 textBoxSend.Clear();  
113.                 textBoxSend.Focus();  
114.             \}  
115.             **catch** (Exception err)  
116.             \{  
117.                 MessageBox.Show(err.Message, "发送失败");  
118.             \}  
119.         \}  
120.   
121.         /// </summary>  
122.         /// <param name="ar">IAsyncResult接口</param>  
123.         **public** **void** SendCallback(IAsyncResult ar)  
124.         \{  
125.             UdpClient udpClient = (UdpClient)ar.AsyncState;  
126.             udpClient.EndSend(ar);  
127.             String message = **string**.Format("向\{0\}发送：\{1\}", iep.ToString(), sendMessage);  
128.             AddItem(listBoxStatus, message);  
129.             udpClient.Close();  
130.         \}  
131.           
132.         /// <summary>  
133.         /// 单击发送按钮触发的事件  
134.         /// </summary>  
135.         **private** **void** buttonSend\_Click(**object** sender, EventArgs e)  
136.         \{  
137.             sendData();  
138.         \}  
139.         /// <summary>  
140.         /// 在textBoxSend中按下并释放Enter键后触发的事件  
141.         /// </summary>  
142.         **private** **void** textBoxData\_KeyPress(**object** sender, KeyPressEventArgs e)  
143.         \{  
144.             **if** (e.KeyChar == (**char**)Keys.Enter)  
145.                 sendData();  
146.         \}  
147.         /// <summary>  
148.         /// 关闭窗体，释放资源  
149.         /// </summary>  
150.         /// <param name="sender"></param>  
151.         /// <param name="e"></param>  
152.         **private** **void** FormChat\_FormClosing(**object** sender, FormClosingEventArgs e)  
153.         \{  
154.             receiveClient.Close();  
155.         \}  
156.           
157.         **delegate** **void** AddListBoxItemDelegate(ListBox listbox, **string** text);  
158.         **private** **void** AddItem(ListBox listbox, **string** text)  
159.         \{  
160.             **if** (listbox.InvokeRequired)  
161.             \{  
162.                 AddListBoxItemDelegate d = AddItem;  
163.                 listbox.Invoke(d, **new** **object**\[\] \{ listbox, text \});  
164.             \}  
165.             **else**  
166.             \{  
167.                 listbox.Items.Add(text);  
168.                 listbox.SelectedIndex = listbox.Items.Count - 1;  
169.                 listbox.ClearSelected();  
170.             \}  
171.         \}  
172.   
173.         **delegate** **void** ClearTextBoxDelegate();  
174.         **private** **void** ClearTextBox()  
175.         \{  
176.             **if** (textBoxSend.InvokeRequired)  
177.             \{  
178.                 ClearTextBoxDelegate d = ClearTextBox;  
179.                 textBoxSend.Invoke(d);  
180.             \}  
181.             **else**  
182.             \{  
183.                 textBoxSend.Clear();  
184.                 textBoxSend.Focus();  
185.             \}  
186.         \}  
187.   
188.         **delegate** **void** AddListBoxItemCallback(**string** text);  
189.         **private** **void** AddListBoxItem(**string** text)  
190.         \{  
191.             //如果listBoxReceive被不同的线程访问则通过委托处理；  
192.             **if** (listBoxReceive.InvokeRequired)  
193.             \{  
194.                 **this**.Invoke(listBoxCallback, text);  
195.             \}  
196.             **else**  
197.             \{  
198.                 listBoxReceive.Items.Add(text);  
199.                 listBoxReceive.SelectedIndex = listBoxReceive.Items.Count - 1;  
200.                 listBoxReceive.ClearSelected();  
201.             \}  
202.         \}  
203.     \}  
204. \}

界面设计：  
![1346385077_4373.jpg][]

[view plain]: http://blog.csdn.net/huangwenhua5000/article/details/7928596#
[1346385077_4373.jpg]: https://img-my.csdn.net/uploads/201208/31/1346385077_4373.jpg