稳扎稳打Silverlight(54) - 4.0通信之对UDP协议的支持: 通过 UdpAnySourceMulticastClient 实现 ASM（Any Source Multicast），即

//  启动多播的安全策略服务
private   void  LaunchMulticastPolicyServer()
{
     /*
     * Silverlight 程序加入多播组之前，会通过 UDP 端口 9430 发送初始消息到多播组，然后服务端返回相应的安全策略（详见文档）
     * 为了方便下发安全策略，可以引用 Microsoft.Silverlight.PolicyServers.dll 程序集，其封装了相关的方法
      */

     //  本例的安全策略配置结果为：授权通过 UDP 端口 3003 问多播组 224.0.0.1，授权通过 UDP 端口 3006 问多播组 224.0.0.1
    MulticastPolicyConfiguration config  =   new  MulticastPolicyConfiguration();
    config.AnysourceConfiguration.Add( " * " ,  new  Multicastresource(Ipaddress.Parse( " 224.0.0.1 " ),  3006 ));  //  配置 ASM 的安全策略

    MulticastPolicyServer server  =   new  MulticastPolicyServer(config);
    server.Start();

    Showmessage( " 多播的安全策略服务已启动 " );
}

using  System;
using  System.Net;
using  System.Windows;
using  System.Windows.Controls;
using  System.Windows.Documents;
using  System.Windows.Ink;
using  System.Windows.Input;
using  System.Windows.Media;
using  System.Windows.Media.Animation;
using  System.Windows.Shapes;

namespace  Silverlight40.Communication
{
     public   class  UdpPacketEventArgs : EventArgs
    {
         //  UDP 包的内容
         public   String  message {  get ;  set ; }
         //  UDP 包的来源的 IPEndPoint 
         public  IPEndPoint source {  get ;  set ; }

         public  UdpPacketEventArgs( byte [] data, IPEndPoint sourcE)
        {
             this .message  =  System.Text.Encoding.UTF8.GetString(data,  0 , data.Length);
             this .source  =  source;
        }
    }
}

/*
 * 通过 UdpAnysourceMulticastClient 实现 ASM（Any source Multicast），即“任意源多播”
 * 多播组基于 IGMP（Internet Group Management Protocol），即“Internet组管理协议”
 * 
 * UdpAnysourceMulticastClient - 一个发送信息到多播组并从任意源接收多播信息的客户端，即 ASM 客户端
 *     BeginJoinGroup(), EndJoinGroup() - 加入多播组的异步方法
 *     BeginReceiveFromGroup(), EndReceiveFromGroup() - 从多播组接收信息的异步方法（可以理解为接收多播组内所有成员发送的信息）
 *     BeginSendToGroup(), EndSendToGroup() - 发送信息到多播组的异步方法（可以理解为发送信息到多播组内的全部成员）
 *     receiveBufferSize - 接收信息的缓冲区大小
 *     SendBufferSize - 发送信息的缓冲区大小
 *     
 *     BeginSendTo(), EndSendTo() - 发送信息到指定目标的异步方法
 *     Blocksource() - 阻止指定源，以便不再接收该源发来的信息
 *     Unblocksource() - 取消阻止指定源
 *     MulticastLoopBACk - 发出的信息是否需要传给自己
 * 
 * 本例为一个通过 UdpAnysourceMulticastClient 实现 ASM 客户端的帮助类
  */

using  System;
using  System.Net;
using  System.Windows;
using  System.Windows.Controls;
using  System.Windows.Documents;
using  System.Windows.Ink;
using  System.Windows.Input;
using  System.Windows.Media;
using  System.Windows.Media.Animation;
using  System.Windows.Shapes;

using  System.Text;
using  System.Net.sockets;

namespace  Silverlight40.Communication
{
     public   class  UdpAnysourceMulticastChAnnel : IDisposable
    {
         private  UdpAnysourceMulticastClient _client;

         //  接收信息的缓冲区
         private   byte [] _buffer;
         //  此客户端是否加入了多播组
         private   bool  _isJoined;

         ///   <sumMary>
         ///  构造函数
         ///   </sumMary>
         ///   <param NAME="groupaddress"> 多播组地址 </param>
         ///   <param NAME="port"> 客户端端口 </param>
         ///   <param NAME="maxmessageSize"> 接收信息的缓冲区大小 </param>
         public  UdpAnysourceMulticastChAnnel(Ipaddress groupaddress,  int  port,  int  maxmessageSizE)
        {
            _buffer  =   new   byte [maxmessageSize];
             //  实例化 ASM 客户端，需要指定的参数为：多播组地址；客户端端口
            _client  =   new  UdpAnysourceMulticastClient(groupaddress, port);
        }

         //  收到多播信息后触发的事件
         public   event  EventHandler < UdpPacketEventArgs >  received;
         private   void  OnReceived(IPEndPoint source,  byte [] data)
        {
            var handler  =  received;
             if  (handler  !=   null )
                handler( this ,  new  UdpPacketEventArgs(data, sourcE));
        }

         //  加入多播组后触发的事件
         public   event  EventHandler opening;
         private   void  Onopening()
        {
            var handler  =  opening;
             if  (handler  !=   null )
                handler( this , EventArgs.Empty);
        }

         //  断开多播组后触发的事件
         public   event  EventHandler Closing;
         private   void  OnClosing()
        {
            var handler  =  Closing;
             if  (handler  !=   null )
                handler( this , EventArgs.Empty);
        }

         ///   <sumMary>
         ///  加入多播组
         ///   </sumMary>
         public   void  open()
        {
             if  ( ! _isJoined)
            {
                _client.beginJoinGroup(
                    result  =>
                    {
                        _client.EndJoinGroup(result);
                        _isJoined  =   true ;
                        Deployment.Current.Dispatcher.beginInvoke(
                            ()  =>
                            {
                                Onopening();
                                receive();
                            });
                    },  null );
            }
        }

         public   void  Close()
        {
            _isJoined  =   false ;
            OnClosing();
            Dispose();
        }

         ///   <sumMary>
         ///  发送信息到多播组，即发送信息到多播组内的所有成员
         ///   </sumMary>
         public   void  Send( String  msg)
        {
             if  (_isJoined)
            {
                 byte [] data  =  Encoding.UTF8.GetBytes(msg);

                _client.beginSendToGroup(data, data.Length,
                    result  =>
                    {
                        _client.EndSendToGroup(result);
                    },  null );
            }
        }

         ///   <sumMary>
         ///  从多播组接收信息，即接收多播组内所有成员发送的信息
         ///   </sumMary>
         private   void  receive()
        {
             if  (_isJoined)
            {
                array.Clear(_buffer, _buffer.Length);

                _client.beginReceiveFromGroup(_buffer, _buffer.Length,
                    result  =>
                    {
                        IPEndPoint source;
                        _client.EndReceiveFromGroup(result,  out  sourcE);
                        Deployment.Current.Dispatcher.beginInvoke(
                            ()  =>
                            {
                                OnReceived(source, _buffer);
                                receive();
                            });
                    },  null );
            }
        }

         public   void  Dispose()
        {
             if  (_client  !=   null )
                _client.Dispose();
        }
    }
}

< navigation:Page  x:Class ="Silverlight40.Communication.UdpAnysourceMulticastClientDemo"  
           xmlns ="http://scheR_369_11845@as.microsoft.com/winfx/2006/xaml/presentation"  
           xmlns:x ="http://scheR_369_11845@as.microsoft.com/winfx/2006/xaml"  
           xmlns:d ="http://scheR_369_11845@as.microsoft.com/expression/blend/2008"
           xmlns:mc ="http://scheR_369_11845@as.openxmlformats.org/markup-compatibility/2006"
           xmlns:navigation ="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Navigation"
           title ="UdpAnysourceMulticastClientDemo Page" >
     < Grid  x:Name ="LayoutRoot" >
        
         < Grid.columnDeFinitions >
             < columnDeFinition  Width ="80"   />
             < columnDeFinition  Width ="*"   />
             < columnDeFinition  Width ="60"   />
         </ Grid.columnDeFinitions >
         < Grid.RowDeFinitions >
             < RowDeFinition  Height ="*"   />
             < RowDeFinition  Height ="40"   />
         </ Grid.RowDeFinitions >

         < ListBox  Name ="lstAllMsg"  Grid.columnSpan ="3"  Margin ="6"   />
         < TextBox  Name ="txtUserName"  Grid.Row ="1"  Grid.column ="0"  Margin ="6"   />
         < TextBox  Name ="txtSendMsg"  Grid.Row ="1"  Grid.column ="1"  textwrapping ="Wrap"  Margin ="6"  KeyDown ="txtmsg_KeyDown"   />
         < Button  Name ="btnSend"  Grid.Row ="1"  Grid.column ="2"  Margin ="6"  Content ="发送"  Click ="btnSend_Click"   />

     </ Grid >
</ navigation:Page >

/*
 * 用于演示 ASM 的客户端
  */

using  System;
using  System.Collections.Generic;
using  System.Linq;
using  System.Net;
using  System.Windows;
using  System.Windows.Controls;
using  System.Windows.Documents;
using  System.Windows.Input;
using  System.Windows.Media;
using  System.Windows.Media.Animation;
using  System.Windows.Shapes;
using  System.Windows.Navigation;

namespace  Silverlight40.Communication
{
     public   partial   class  UdpAnysourceMulticastClientDemo : Page
    {
         private  UdpAnysourceMulticastChAnnel _chAnnel;

         public  UdpAnysourceMulticastClientDemo()
        {
            initializeComponent();
        }

         protected   override   void  OnNavigatedTo(NavigationEventArgs E)
        {
            txtUserName.Text  =   " 匿名 "   +   new  random().Next( 1000 ,  9999 ).ToString();

            _chAnnel  =   new  UdpAnysourceMulticastChAnnel(Ipaddress.Parse( " 224.0.0.1 " ),  3006 ,  2048 ); 
            _chAnnel.opening  +=   new  EventHandler(_chAnnel_opening);
            _chAnnel.Received  +=   new  EventHandler < UdpPacketEventArgs > (_chAnnel_Received);
            _chAnnel.Closing  +=   new  EventHandler(_chAnnel_Closing);

            Application.Current.Exit  +=   new  EventHandler(Current_Exit);

            _chAnnel.open();
        }

         void  _chAnnel_opening( object  sender, EventArgs E)
        {
            _chAnnel.Send( String .Format( " {0}: 进来了 - [{1}] " , txtUserName.Text, datetiR_369_11845@e.Now.ToString( " HH:mm:ss " )));
        }

         void  _chAnnel_Received( object  sender, UdpPacketEventArgs E)
        {
             //  因为已经指定了接收信息的缓冲区大小是 2048 ，所以如果信息不够 2048 个字节的的话，空白处均为“\0”
             String  message  =   String .Format( " {0} - 来自：{1} " , e.message.TrimEnd( ' \0 ' ), e.source.ToString()); 
            lstAllMsg.Items.Insert( 0 , messagE); 
        }

         void  _chAnnel_Closing( object  sender, EventArgs E)
        {
            _chAnnel.Send( String .Format( " {0}: 离开了 - [{1}] " , datetiR_369_11845@e.Now.ToString( " HH:mm:ss " )));
        }

         void  Current_Exit( object  sender, EventArgs E)
        {
            _chAnnel.Dispose();
        }

         private   void  btnSend_Click( object  sender, routedEventArgs E)
        {
            SendMsg();
        }

         private   void  txtmsg_KeyDown( object  sender, KeyEventArgs E)
        {
             if  (e.Key  ==  Key.Enter)
                SendMsg();
        }

         private   void  SendMsg()
        {
            _chAnnel.Send( String .Format( " {0}: {1} - [{2}] " , txtSendMsg.Text, datetiR_369_11845@e.Now.ToString( " HH:mm:ss " )));
            txtSendMsg.Text  =   "" ;
        }
    }
}