（三）一个工作任务引起的乱战——udp通信

先上代码。该代码是在问度娘的过程中搜到的，自己实验运行了下，可以使用（vs2010 net fram4.0）。服务端代码：

using System;using System.Collections.Generic;
using System.Text;
using System.Net;
using System.Net.Sockets;
namespace UDP
{
class Program
{
static void Main(string[] args)
{
int recv;
byte[] data = new byte[1024];

//得到本机IP，设置TCP端口号
IPEndPoint ip = new IPEndPoint(IPAddress.Any, 8001);
Socket newsock = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

//绑定网络地址
newsock.Bind(ip);
Console.WriteLine("This is a Server, host name is {0}", Dns.GetHostName());

//等待客户机连接
Console.WriteLine("Waiting for a client");

//得到客户机IP
IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
EndPoint Remote = (EndPoint)(sender);
recv = newsock.ReceiveFrom(data, ref Remote);
Console.WriteLine("Message received from {0}: ", Remote.ToString());
Console.WriteLine(Encoding.ASCII.GetString(data, 0, recv));

//客户机连接成功后，发送信息
string welcome = "你好!见到你很高兴！ ";

//字符串与字节数组相互转换
data = Encoding.ASCII.GetBytes(welcome);

//发送信息
newsock.SendTo(data, data.Length, SocketFlags.None, Remote);
while (true)
{
data = new byte[1024];
//发送接受信息
recv = newsock.ReceiveFrom(data, ref Remote);
Console.WriteLine(Encoding.ASCII.GetString(data, 0, recv));
newsock.SendTo(data, recv, SocketFlags.None, Remote);
}
}
}
}

客户端代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Sockets;
namespace UDPClient
{
class Program
{
static void Main(string[] args)
{
byte[] data = new byte[1024];
string input, stringData;
//构建TCP 服务器
Console.WriteLine("This is a Client, host name is {0}", Dns.GetHostName());
//设置服务IP，设置TCP端口号
IPEndPoint ip = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 8001);
//定义网络类型，数据连接类型和网络协议UDP
Socket server = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
string welcome = "你好! ";
data = Encoding.ASCII.GetBytes(welcome);
server.SendTo(data, data.Length, SocketFlags.None, ip);
IPEndPoint sender = new IPEndPoint(IPAddress.Any, 0);
EndPoint Remote = (EndPoint)sender;
data = new byte[1024];
//对于不存在的IP地址，加入此行代码后，可以在指定时间内解除阻塞模式限制
int recv = server.ReceiveFrom(data, ref Remote);
Console.WriteLine("Message received from {0}: ", Remote.ToString());
Console.WriteLine(Encoding.ASCII.GetString(data, 0, recv));
while (true)
{
input = Console.ReadLine();
if (input == "exit")
break;
server.SendTo(Encoding.ASCII.GetBytes(input), Remote);
data = new byte[1024];
recv = server.ReceiveFrom(data, ref Remote);
stringData = Encoding.ASCII.GetString(data, 0, recv);
Console.WriteLine(stringData);
}
Console.WriteLine("Stopping Client.");
server.Close();
}
}
}

运行后，服务端与客户端能正确通信。
这些代码虽然在实际工作处理中不是特别完整，但是可以提供一个思路。