Mina.Net实现的UDP多路广播

主要用于未确定主机地址的情况下，可以使用多路广播和服务端通信，下面是官方提供的DEMO。

using System;

using System.Net;

using System.Net.Sockets;

using System.Text;

using Mina.Core.Session;

using Mina.Filter.Codec;

using Mina.Filter.Codec.TextLine;

using Mina.Transport.Socket;

namespace MulticastUDP

{

    /// <summary>

    /// UDP Multicast

    ///

    /// See http://msdn.microsoft.com/en-us/library/system.net.sockets.multicastoption%28v=vs.110%29.aspx

    /// </summary>

    class Program

    {

        static IPAddress mcastAddress;

        static int mcastPort;

        static void Main(string[] args)

        {

            // Initialize the multicast address group and multicast port.

            // Both address and port are selected from the allowed sets as

            // defined in the related RFC documents. These are the same

            // as the values used by the sender.

            //mcastAddress = IPAddress.Parse("224.168.100.2");

            mcastAddress = IPAddress.Parse("224.168.100.1");

            mcastPort = ;

            StartMulticastAcceptor();

            StartMulticastConnector();

            Console.ReadLine();

        }

        static void StartMulticastAcceptor()

        {

            IPAddress localIPAddr = IPAddress.Any;

            AsyncDatagramAcceptor acceptor = new AsyncDatagramAcceptor();

            acceptor.FilterChain.AddLast("codec", new ProtocolCodecFilter(new TextLineCodecFactory(Encoding.UTF8)));

            // Define a MulticastOption object specifying the multicast group

            // address and the local IPAddress.

            // The multicast group address is the same as the address used by the client.

            MulticastOption mcastOption = new MulticastOption(mcastAddress, localIPAddr);

            acceptor.SessionConfig.MulticastOption = mcastOption;

            acceptor.SessionOpened += (s, e) =>

            {

                Console.WriteLine("Opened: {0}", e.Session.RemoteEndPoint);

            };

            acceptor.MessageReceived += (s, e) =>

            {

                Console.WriteLine("Received from {0}: {1}", e.Session.RemoteEndPoint, e.Message);

            };

            acceptor.Bind(new IPEndPoint(localIPAddr, mcastPort));

            Console.WriteLine("Acceptor: current multicast group is: " + mcastOption.Group);

            Console.WriteLine("Acceptor: current multicast local address is: " + mcastOption.LocalAddress);

            Console.WriteLine("Waiting for multicast packets.......");

        }

        static void StartMulticastConnector()

        {

            IPAddress localIPAddr = IPAddress.Any;

            IPEndPoint mcastEP = new IPEndPoint(mcastAddress, mcastPort);

            AsyncDatagramConnector connector = new AsyncDatagramConnector();

            connector.FilterChain.AddLast("codec", new ProtocolCodecFilter(new TextLineCodecFactory(Encoding.UTF8)));

            // Set the local IP address used by the listener and the sender to

            // exchange multicast messages.

            connector.DefaultLocalEndPoint = new IPEndPoint(localIPAddr, );

            // Define a MulticastOption object specifying the multicast group

            // address and the local IP address.

            // The multicast group address is the same as the address used by the listener.

            MulticastOption mcastOption = new MulticastOption(mcastAddress, localIPAddr);

            connector.SessionConfig.MulticastOption = mcastOption;

            // Call Connect() to force binding to the local IP address,

            // and get the associated multicast session.

            IoSession session = connector.Connect(mcastEP).Await().Session;

            // Send multicast packets to the multicast endpoint.

            session.Write("hello 1", mcastEP);

            session.Write("hello 2", mcastEP);

            session.Write("hello 3", mcastEP);

        }

    }

}