C#实现TCP和UDP通信的示例详解

using System.Net.Sockets;
using System.Net;
using System.Text;

//由于收发都在本机，所以只用一个IP地址
IPAddress addr = IPAddress.Parse("127.0.0.1");

var ptLocal = new IPEndPoint(addr, 9001);  //本机节点，用于发送
var ptDst = new IPEndPoint(addr, 9002);    //目标节点

var udp = new UdpClient(ptLocal);          //在本地建立udp服务
byte[] buffer = Encoding.UTF8.GetBytes("hello");
udp.Send(buffer, buffer.Length, ptDst);    //将内容发给ptDst

// 前面的代码和发送代码一样
while (true)
{
    var received = udp.Receive(ref ptDst);
    string info = Encoding.UTF8.GetString(received);
    info =$" {ptDst.Address}:{ptDst.Port}:{info}";
    Console.WriteLine(info);
    byte[] buf = Encoding.UTF8.GetBytes("What are our children's names");
    udp.Send(buf, buf.Length, ptDst);    //将内容发给ptDst
}

// 引用的命名空间还是上面这些
TcpClient tcp = new TcpClient("127.0.0.1", 9002);
NetworkStream n = tcp.GetStream();
var w = new BinaryWriter(n);
byte[] buffer = Encoding.UTF8.GetBytes("hello");
w.Write(buffer, 0, buffer.Length);
w.Flush();

TcpListener serv = new TcpListener(IPAddress.Any, 9002);
serv.Start();

Byte[] bytes = new Byte[256];
int i;
while (true)
{
    var c = serv.AcceptTcpClient();
    var n = c.GetStream();
    while ((i = n.Read(bytes, 0, bytes.Length)) != 0)
    {
        var msg = Encoding.ASCII.GetString(bytes, 0, i);
        Console.WriteLine($"Received: {msg}");
        msg += ", too";
        var data = Encoding.ASCII.GetBytes(msg);
        n.Write(data, 0, data.Length);
    }
}