C# 异步UDP通讯

C#下的Socket编程有同步和异步之，他们的具体区别偶还是没有完全搞清楚，最近研究的了一下这方便的东西，写在此做个记录。

在UDp监听某一端口通讯的时候，可以采用同步，使用线程，然后接受阻塞的模式，但是还可以使用异步的方法，比如下列子：
 

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

namespace Server
{

    public class UdpServer
    {

        public class UdpState
        {
            public IPEndPoint e = null;
            public UdpClient u = null;
        }
        public static UdpState s = new UdpState();

        public static void ReceiveMessages()
        {
            IPEndPoint e = new IPEndPoint(IPAddress.Any, 10001);
            UdpClient u = new UdpClient(e);
            s.u = u;
            u.BeginReceive(new AsyncCallback(ReceiveCallback), s);
        }

        /// <summary>
        /// UDP异步回调函数
        /// </summary>
        /// <param name="ar"></param>
        public static void ReceiveCallback(IAsyncResult ar)
        {
            UdpClient u = (UdpClient)((UdpState)(ar.AsyncState)).u;
            Byte[] receiveBytes = u.EndReceive(ar, ref s.e);
            u.BeginReceive(new AsyncCallback(ReceiveCallback), ar.AsyncState);//重新开启异步接受
            string receiveString = Encoding.ASCII.GetString(receiveBytes);
            Console.WriteLine("Received: {0}", receiveString);
        }

    }
}

 

    /// <summary>
    /// 简单的发送客户端类
    /// </summary>
    public class UdpSendClient
    {
        public static UdpClient udpClient = new UdpClient();
        public static void send()
        {
            udpClient.Connect("127.0.0.1", 10001);
            Byte[] sendBytes = Encoding.ASCII.GetBytes("sendteststring");
            udpClient.Send(sendBytes, sendBytes.Length);
        }
    }

  

想说的是这个异步接受就一定要得绑定端口，如果不绑定会报异常。