利用Flash XMLSocket实现”服务器推”技术

利用Flash XML Socket实现”服务器推”技术的基础是：1.Flash提供了XMLSocket类，服务器利用Socket向Flash发送数据；2.JavaScript和Flash的紧密结合，JavaScript和as可以相互调用。

具体实现的方法：在HTML页面中陷入一个使用了XMLSocket类的Falsh程序。JavaScript通过调用此Flash程序提供的套接口接口与服务端的套接口进行通信。JavaScript在收到服务器端以XML格式传送的信息控制HTML的Dom对象改变页面的内容显示。

一、XMLSocket简介

XMLSocket 类实现了客户端套接字，这使得运行 Flash Player 的计算机可以与由 IP 地址或域名标识的服务器计算机进行通信。 对于要求滞后时间较短的客户端/服务器应用程序，如实时聊天系统，XMLSocket 类非常有用。 传统的基于 HTTP 的聊天解决方案频繁轮询服务器，并使用 HTTP 请求来下载新的消息。 与此相对照，XMLSocket 聊天解决方案保持与服务器的开放连接，这一连接允许服务器即时发送传入的消息，而无需客户端发出请求。 若要使用 XMLSocket 类，服务器计算机必须运行可识别 XMLSocket 类使用的协议的守护程序。可以参考XMLSocket简介。

二、AS与JavaScript通信

利用ExternalInterface可以实现AS与JavaScript的通信，具体请看Flex与JavaScript交互。

三、实现Socket

客户端Flex：

 1:  <?xml version="1.0" encoding="utf-8"?>

 2:  <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">

 3:      <mx:Script>

 4:          <![CDATA[

 5:              private var socket:XMLSocket=new XMLSocket();

 6:   

 7:              private function ConncetServer():void

 8:              {

 9:                  socket.addEventListener(DataEvent.DATA,OnReceived);

10:                  socket.addEventListener(Event.CONNECT , onConnected);

11:                  this.socket.connect("127.0.0.1",8080);

12:              }

13:   

14:              private function onConnected(event:Event):void

15:              {

16:                  socket.send("begin connect");

17:                  this.txtContent.text=this.txtContent.text+"conect success\n";

18:              }

19:   

20:              private function Send():void

21:              {

22:                  socket.send("message from flex");

23:              }

24:   

25:               private function OnReceived(event:DataEvent):void

26:               {    

27:                  trace("receive data.");

28:                  this.txtContent.text=this.txtContent.text+"\n"+ event.text;

29:               }

30:          ]]>

31:      </mx:Script>

32:      

33:      <mx:Button label="Connect" fontSize="12" id="btnConnect" left="10" top="20" click="ConncetServer()"/>

34:      <mx:Button label="Send" fontSize="12" id="btnSend" left="80" top="20" click="Send();" />

35:      <mx:TextArea borderColor="#010A10" id="txtContent" left="10" top="110" right="10" bottom="10" backgroundColor="#DEEEF3" cornerRadius="12"/>

36:  </mx:Application>

Socket服务端：

  1:  using System;

  2:  using System.Collections.Generic;

  3:  using System.Linq;

  4:  using System.Text;

  5:  using System.Net;

  6:  using System.Net.Sockets;

  7:  using System.Threading;

  8:   

  9:  namespace SocketServer

 10:  {

 11:      class Program

 12:      {

 13:          static bool ServiceStartFlag = false;

 14:          static Socket socket;

 15:          static Thread thread;

 16:   

 17:          static void Main(string[] args)

 18:          {

 19:              socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

 20:              IPHostEntry ieh = Dns.GetHostEntry("localhost");

 21:              IPAddress localServerIP = ieh.AddressList[1];

 22:              IPEndPoint localIPEndPoint = new IPEndPoint(localServerIP, 8080);

 23:   

 24:              socket.Bind(localIPEndPoint);

 25:              socket.Listen(600);

 26:   

 27:              thread = new Thread(new ThreadStart(AcceptClient));

 28:              thread.IsBackground = true;

 29:              thread.Start();

 30:   

 31:              Console.ReadLine();

 32:          }

 33:   

 34:          static void AcceptClient()

 35:          {

 36:              ServiceStartFlag = true;

 37:   

 38:              while (ServiceStartFlag)

 39:              {

 40:                  try

 41:                  {

 42:                      Socket newSocket = socket.Accept();

 43:                      string onemessge = "<cross-domain-policy><allow-access-from domain=\"" + "*" + "\" to-ports=\"8080\"/></cross-domain-policy>\0";

 44:   

 45:                      byte[] tmpBytes = Encoding.UTF8.GetBytes(onemessge);

 46:                      newSocket.Send(tmpBytes);

 47:   

 48:                      Thread newThread = new Thread(new ParameterizedThreadStart(ReadMsg));

 49:                      newThread.IsBackground = true;

 50:                      object obj = newSocket;

 51:                      newThread.Start(obj);

 52:                  }

 53:                  catch (SocketException ex)

 54:                  {

 55:   

 56:   

 57:   

 58:                  }

 59:              }

 60:          }

 61:   

 62:          static void ReadMsg(object obj)

 63:          {

 64:              Socket socket = (Socket)obj;

 65:   

 66:              byte[] byteMessage = null; ;

 67:   

 68:              while (ServiceStartFlag)

 69:              {

 70:                  try

 71:                  {

 72:                      if (socket.Connected)

 73:                      {

 74:   

 75:                          byteMessage = new byte[1000];

 76:                          int len = socket.Receive(byteMessage);

 77:                          if (len > 0)

 78:                          {

 79:                              string sTime = DateTime.Now.ToShortTimeString();

 80:   

 81:                              string msg = sTime + ":" + "Message from:";

 82:   

 83:                              msg += socket.RemoteEndPoint.ToString() + Encoding.UTF8.GetString(byteMessage);

 84:                              Console.WriteLine(msg);

 85:                              byteMessage = null;

 86:   

 87:                              byte[] tmpBytes = Encoding.UTF8.GetBytes("Sended Sucessed!\0");

 88:   

 89:                              socket.Send(tmpBytes);

 90:                          }

 91:   

 92:   

 93:                      }

 94:                  }

 95:                  catch (SocketException ex)

 96:                  {

 97:                      Console.WriteLine(ex.Message);

 98:                  }

 99:              }

100:          }

101:      }

102:  }

103:   

104:   

运行结果：