flex4局域网(LAN)的P2P通讯

Aug 29

bearjia , 10:35 , Flex相关 , 评论(1) , 引用(0) , 阅读(1737) , Via 本站原创

flash在局域网（LAN）建立P2P连接?
其实flash原生就有个IP-only多播！
多播其实是个简单的步骤。

建立一个IP多播连接。指定连接字符串“rtmfp”. 注意，这种方式不能用于一对一通讯。所以不需要设置NetStream为DIRECT_CONNECTIONS，但可以进行RTMFP Group的所有操作。也就是说，只能群发信息。

没错，就是这个了

netConnection.connect("rtmpf:");

一旦连接成功（返回NetConnection.Connect.Success）就可以通过GroupSpecifier建立NetGroup或NetStream.
再设置ipMulticastMemberUpdatesEnabled为true，负责点与点间建立本地的连接，各点使用多播地址和相应端口调用addIPMulticastAddress方法。

多播地址至少以224为起始值，而端口要大于1024 - 即：224.0.0.0:1024
端口越高越好 —— 唯一性。

废话不多说，下面就是完整的代码。

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
         xmlns:s="library://ns.adobe.com/flex/spark"
         xmlns:mx="library://ns.adobe.com/flex/mx" applicationComplete="connect()">
  <fx:Declarations>
    
  </fx:Declarations>

  <fx:Script>
    <![CDATA[
      private var nc:NetConnection;
      private var group:NetGroup;

      [Bindable]
      private var userName:String;

      [Bindable]
      private var connected:Boolean = false;

      private function connect():void{
        nc = new NetConnection();
        nc.addEventListener(NetStatusEvent.NET_STATUS, netStatus);
        nc.connect("rtmfp:");

        userName = "user"+Math.round(Math.random()*1000);
      }

      private function netStatus(event:NetStatusEvent):void{
        writeText(event.info.code);

        switch(event.info.code){
          case "NetConnection.Connect.Success":
            setupGroup();
            break;

          case "NetGroup.Connect.Success":
            connected = true;
            break;

          case "NetGroup.Posting.Notify":
            receiveMessage(event.info.message)
            break;
        }
      }

      private function setupGroup():void{
        var groupspec:GroupSpecifier = new GroupSpecifier("myGroup/groupOne");
        groupspec.postingEnabled = true;
        groupspec.ipMulticastMemberUpdatesEnabled = true;
        groupspec.addIPMulticastAddress("225.225.0.1:30303");

        group = new NetGroup(nc,groupspec.groupspecWithAuthorizations());
        group.addEventListener(NetStatusEvent.NET_STATUS,netStatus);
      }

      private function sendMessage(txt:String):void{
        var message:Object = new Object();
        message.text = txt;
        message.sender = group.convertPeerIDToGroupAddress(nc.nearID);
        message.userName = txtUser.text;

        group.post(message);

        receiveMessage(message);
      }

      public function receiveMessage(message:Object):void{
        writeText(message.userName+": "+message.text);
      }

      private function writeText(txt:String):void{
        txtHistory.text += txt+"\n";
      }

      protected function btnSend_clickHandler(event:MouseEvent):void
      {
        sendMessage( txtMessage.text );
      }

    ]]>
  </fx:Script>
  <s:TextInput text="{userName}" x="10" bottom="10" id="txtUser"/>
  <s:TextInput left="146" right="88" bottom="10" id="txtMessage" enter="btnSend_clickHandler(null)"/>
  <s:TextArea left="10" right="10" top="75" bottom="40" id="txtHistory"/>
  <s:Button enabled="{connected}" label="Send" bottom="10" right="10" click="btnSend_clickHandler(event)" id="btnSend"/>

</s:Application>