C#简单的UDP通信例子加代码

1，UDP客户端

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Net.Sockets;using System.Net;namespace WindowsFormsApplication14{    public partial class Form1 Form    UdpClient udpClient;        IPEndPoint ipEndPoint;        public Form1()        {            InitializeComponent();            udpClient = new UdpClient(12345);            ipEndPoint = new IPEndPoint(IPAddress.Parse("192.168.1.241"), 60000);        }        private void button1_Click(object sender, EventArgs e)        {            //byte[] mybyte = Encoding.Default.GetBytes("nihao");                        byte[] mybyte = new byte[4];            mybyte[0] = 0x12;            mybyte[1] = 0x00;            mybyte[2] = 0x34;            mybyte[3] = 0x00;                        udpClient.Send(mybyte, mybyte.Length,ipEndPoint);        }    }}

2，UDP服务器

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Net.Sockets;using System.Net;namespace WindowsFormsApplication15{    public partial class Form1 Form    UdpClient udpServer;        IPEndPoint ipEndPoint;        public Form1()        {            InitializeComponent();            udpServer = new UdpClient(23456);            ipEndPoint = new IPEndPoint(new IPAddress(0), 0);        }        private void button1_Click(object sender, EventArgs e)        {                        byte[] data = udpServer.Receive(ref ipEndPoint);            MessageBox.Show ( Encoding.Default.GetString(data));        }    }}

3，读接收缓冲区当前数据个数

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Net.Sockets;using System.Net;namespace WindowsFormsApplication15{    public partial class Form1 Form    UdpClient udpServer;        IPEndPoint ipEndPoint;        public Form1()        {            InitializeComponent();            udpServer = new UdpClient(23456);            ipEndPoint = new IPEndPoint(new IPAddress(0), 0);        }        private void button1_Click(object sender, EventArgs e)        {            byte[] outValue =  BitConverter.GetBytes(0);            udpServer.Client.IOControl(IOControlCode.DataToRead, null, outValue);            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            //MessageBox.Show((BitConverter.ToString(outValue)).ToString());        }    }}

 

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

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Net.Sockets;using System.Net;namespace WindowsFormsApplication15{    public partial class Form1 Form    UdpClient udpServer;        IPEndPoint ipEndPoint;        public Form1()        {            InitializeComponent();            udpServer = new UdpClient(23456);            ipEndPoint = new IPEndPoint(new IPAddress(0), 0);            udpServer.Client.Blocking = false//设置为非阻塞模式        private void button1_Click(object sender, EventArgs e)        {            int buffSizeCurrent;            buffSizeCurrent = udpServer.Client.Available;//取得缓冲区当前的数据的个数

MessageBox.Show(buffSizeCurrent.ToString());           if (buffSizeCurrent > 0)     //有数据时候才读，不然会出异常哦            {                byte[] data = udpServer.Receive(ref ipEndPoint);                MessageBox.Show(Encoding.Default.GetString(data));           }        }    }}

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。