编辑“︁C Sharp 套接字编程”︁（章节）

== UDP套接字编程 ==
UDP是无连接的协议，适用于对实时性要求高但允许少量丢包的场景（如视频流）。

=== 服务器端实现 ===
<syntaxhighlight lang="csharp">
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;

class UdpServer
{
    static void Main()
    {
        // 1. 创建UDP Socket
        Socket udpSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
        
        // 2. 绑定端口
        udpSocket.Bind(new IPEndPoint(IPAddress.Any, 9090));
        Console.WriteLine("UDP服务器已启动");
        
        // 3. 接收数据（无需连接）
        byte[] buffer = new byte[1024];
        EndPoint clientEndPoint = new IPEndPoint(IPAddress.Any, 0);
        int bytesRead = udpSocket.ReceiveFrom(buffer, ref clientEndPoint);
        string message = Encoding.UTF8.GetString(buffer, 0, bytesRead);
        Console.WriteLine($"收到来自 {clientEndPoint} 的消息: {message}");
        
        // 4. 发送响应
        udpSocket.SendTo(Encoding.UTF8.GetBytes("UDP响应"), clientEndPoint);
        
        udpSocket.Close();
    }
}
</syntaxhighlight>

=== 客户端实现 ===
<syntaxhighlight lang="csharp">
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;

class UdpClient
{
    static void Main()
    {
        // 1. 创建UDP Socket
        Socket udpSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
        
        // 2. 发送数据（无需连接）
        IPEndPoint serverEndPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 9090);
        udpSocket.SendTo(Encoding.UTF8.GetBytes("Hello, UDP Server!"), serverEndPoint);
        
        // 3. 接收响应
        byte[] buffer = new byte[1024];
        EndPoint remoteEndPoint = new IPEndPoint(IPAddress.Any, 0);
        int bytesRead = udpSocket.ReceiveFrom(buffer, ref remoteEndPoint);
        Console.WriteLine($"收到响应: {Encoding.UTF8.GetString(buffer, 0, bytesRead)}");
        
        udpSocket.Close();
    }
}
</syntaxhighlight>