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：
