1 1，UDP客户端
  2 
  3 using System;
  4 using System.Collections.Generic;
  5 using System.ComponentModel;
  6 using System.Data;
  7 using System.Drawing;
  8 using System.Linq;
  9 using System.Text;
 10 using System.Windows.Forms;
 11 using System.Net.Sockets;
 12 using System.Net;
 13 
 14 namespace WindowsFormsApplication14
 15 {
 16     public partial class Form1 : Form
 17     {
 18         UdpClient udpClient;
 19         IPEndPoint ipEndPoint;
 20 
 21         public Form1()
 22         {
 23             InitializeComponent();
 24             udpClient = new UdpClient(12345);
 25             ipEndPoint = new IPEndPoint(IPAddress.Parse("192.168.1.241"), 60000);
 26         }
 27 
 28         private void button1_Click(object sender, EventArgs e)
 29         {
 30             //byte[] mybyte = Encoding.Default.GetBytes("nihao");
 31             
 32             byte[] mybyte = new byte[4];
 33             mybyte[0] = 0x12;
 34             mybyte[1] = 0x00;
 35             mybyte[2] = 0x34;
 36             mybyte[3] = 0x00;
 37 
 38             
 39             udpClient.Send(mybyte, mybyte.Length,ipEndPoint);
 40         }
 41     }
 42 }
 43 2，UDP服务器
 44 
 45 using System;
 46 using System.Collections.Generic;
 47 using System.ComponentModel;
 48 using System.Data;
 49 using System.Drawing;
 50 using System.Linq;
 51 using System.Text;
 52 using System.Windows.Forms;
 53 using System.Net.Sockets;
 54 using System.Net;
 55 
 56 namespace WindowsFormsApplication15
 57 {
 58     public partial class Form1 : Form
 59     {
 60         UdpClient udpServer;
 61         IPEndPoint ipEndPoint;
 62 
 63         public Form1()
 64         {
 65             InitializeComponent();
 66             udpServer = new UdpClient(23456);
 67             ipEndPoint = new IPEndPoint(new IPAddress(0), 0);
 68         }
 69 
 70         private void button1_Click(object sender, EventArgs e)
 71         {
 72             
 73             byte[] data = udpServer.Receive(ref ipEndPoint);
 74             MessageBox.Show ( Encoding.Default.GetString(data));
 75         }
 76     }
 77 }
 78 3，读接收缓冲区当前数据个数
 79 
 80 using System;
 81 using System.Collections.Generic;
 82 using System.ComponentModel;
 83 using System.Data;
 84 using System.Drawing;
 85 using System.Linq;
 86 using System.Text;
 87 using System.Windows.Forms;
 88 using System.Net.Sockets;
 89 using System.Net;
 90 
 91 namespace WindowsFormsApplication15
 92 {
 93     public partial class Form1 : Form
 94     {
 95         UdpClient udpServer;
 96         IPEndPoint ipEndPoint;
 97 
 98         public Form1()
 99         {
100             InitializeComponent();
101             udpServer = new UdpClient(23456);
102             ipEndPoint = new IPEndPoint(new IPAddress(0), 0);
103         }
104 
105         private void button1_Click(object sender, EventArgs e)
106         {
107             byte[] outValue =  BitConverter.GetBytes(0);
108             udpServer.Client.IOControl(IOControlCode.DataToRead, null, outValue);
109 
110 
111             MessageBox.Show((BitConverter.ToInt32(outValue,0)).ToString());//发送数据发现此时数据增长，但不会超过8K
112             //MessageBox.Show((BitConverter.ToString(outValue)).ToString());
113 
114         }
115     }
116 }
117  
118 
119 4，上例有点复杂，看下面的例子，这个例子还可以说明如何设置非阻塞Socket通讯
120 
121 using System;
122 using System.Collections.Generic;
123 using System.ComponentModel;
124 using System.Data;
125 using System.Drawing;
126 using System.Linq;
127 using System.Text;
128 using System.Windows.Forms;
129 using System.Net.Sockets;
130 using System.Net;
131 
132 namespace WindowsFormsApplication15
133 {
134     public partial class Form1 : Form
135     {
136         UdpClient udpServer;
137         IPEndPoint ipEndPoint;
138 
139         public Form1()
140         {
141             InitializeComponent();
142             udpServer = new UdpClient(23456);
143             ipEndPoint = new IPEndPoint(new IPAddress(0), 0);
144             udpServer.Client.Blocking = false; //设置为非阻塞模式
145         }
146 
147         private void button1_Click(object sender, EventArgs e)
148         {
149             int buffSizeCurrent;
150             buffSizeCurrent = udpServer.Client.Available;//取得缓冲区当前的数据的个数            
151              MessageBox.Show(buffSizeCurrent.ToString());
152            if (buffSizeCurrent > 0)     //有数据时候才读，不然会出异常哦
153             {
154                 byte[] data = udpServer.Receive(ref ipEndPoint);
155                 MessageBox.Show(Encoding.Default.GetString(data));
156            }
157         }
158     }
159 }
160 5，上面的例子是同步非阻塞的例子，但默认是同步阻塞的。除此之外还有异步的通讯方式（事件通知的方式触发），稍微复杂，以后补充。