Flex与.NET互操作(十二)：FluorineFx.Net的及时通信应用(Remote Shared Objects)(三)

         远程共享对象(Remote Shared Objects) 可以用来跟踪、存储、共享以及做多客户端的数据同步操作。只要共享对象上的数据发生了改变，将会把最新数据同步到所有连接到该共享对象的应用程序客户端。FluorineFx所提供的远程共享对象(Remote Shared Objects)和FMS的共享对象的功能是一样，对于熟悉FMS开发的朋友来说,学习FluorineFx的远程共享对象是非常简单的。

      共享对象可以在服务器端创建，也可以在客户端创建。在客户端创建共享对象的方法和使用FMS开发是一样的，创建一个NetConnection对象，通过该对象的connect()方法连接到服务器，然后通过SharedObject.getRemote()方法就可以在客户端创建一个远程共享对象。如下实例代码：

private  function connectionServer(): void
{
    var nc:NetConnection  =   new  NetConnection();
    nc.connect( " rtmp://localhost:1617/SOAPP " , " username " , " password " )
    nc.addEventListener(NetStatusEvent.NET_STATUS,onStatusHandler);
    nc.client  =   this ;
}

private  function onStatusHandler( event :NetStatusEvent): void
{
     if ( event .info.code  ==   " NetConnectin.Connect.Success " )
    {
        createSharedObject();
    }
}

private  function createSharedObject(): void
{
    var so:SharedObject  =  SharedObject.getRemote( " OnLineUsers " ,nc.uri, false );
    so.addEventListener(SyncEvent.SYNC,onSyncHandler);
    so.connect( this .nc);
    so.client  =   this ;
}

private  function onSyncHandler( event :SyncEvent): void
{
   // ..do other
}

 

      在FluorineFx的服务器端创建远程共享对象和FMS有很大的区别，FluorineFx的ISharedObjectService接口提供了专门用于创建远程共享对象的方法CreateSharedObject()，ApplicationAdapter实现了此接口方法。定义如下：

 

public   bool  CreateSharedObject(IScope scope,  string  name,  bool  persistent)
{
      ISharedObjectService service  =  (ISharedObjectService)ScopeUtils.GetScopeService(scope,  typeof (ISharedObjectService));
       return  service.CreateSharedObject(scope, name, persistent);
}

 

      如果要在服务器端创建远程共享对象，直接调用ApplicationAdapter类中的CreateSharedObject()方法就可以。如下在FluorineFx服务器端创建远程共享对象的代码块：

ISharedObject users_so  =  GetSharedObject(connection.Scope,  " OnLineUsers " );
if  (users_so  ==   null )
{
        // 创建共享对象
        CreateSharedObject(connection.Scope,  " OnLineUsers " ,  false );
        users_so  =  GetSharedObject(connection.Scope,  " OnLineUsers " );
}

 

      要想更新共享对象里的数据客户端还是使用setProperty()方法，而FluorineFx的服务器更新共享对象的方法则与FMS不一样，使用的是FluorineFx.Messaging.Api.IAttributeStore接口提供的SetAttribute()和RemoveAttribute()方法来更新共享对象里的数据。

      陆续介绍了这么多，下面通过一个案例来看看该这么去应用远程共享对象。比如做IM、视频聊天、视频会议等及时通信类型的应用中，用户上线下线的频率非常高，这时候我们就可以使用远程共享对象去做在线用户的数据同步。 

      首先建立FluorineFx服务库，并建立一个应用类继承于ApplicationAdapter,通过重写ApplicationAdapter的相关方法来实现应用程序的不同需求，详细如下代码块：

using  System;
using  System.Collections.Generic;
using  System.Text;
using  FluorineFx.Messaging.Adapter;
using  FluorineFx;
using  FluorineFx.Messaging.Api;
using  System.Diagnostics;
using  FluorineFx.Messaging.Api.SO;
using  FluorineFx.Exceptions;
using  FluorineFx.Context;
using  FluorineFx.Messaging.Api.Service;
using  System.Collections;
using  Fx.Adapter.DTO;

namespace  Fx.Adapter
{
     ///   <summary>
     ///  自定义ApplicationAdapter
     ///   </summary>
    [RemotingService]
     public   class  MyApp : ApplicationAdapter
    {
         ///   <summary>
         ///  应用程序启动
         ///   </summary>
         ///   <param name="application"></param>
         ///   <returns></returns>
         public   override   bool  AppStart(IScope application)
        {
            Trace.WriteLine( " 应用程序启动 " );
             return   true ;
        }

         ///   <summary>
         ///  房间启动
         ///   </summary>
         ///   <param name="room"></param>
         ///   <returns></returns>
         public   override   bool  RoomStart(IScope room)
        {
            Trace.WriteLine( " 房间启动 " );
             if  ( ! base .RoomStart(room))
                 return   false ;
             return   true ;
        }

         ///   <summary>
         ///  接收客户端的连接
         ///   </summary>
         ///   <param name="connection"></param>
         ///   <param name="parameters"></param>
         ///   <returns></returns>
         public   override   bool  AppConnect(IConnection connection,  object [] parameters)
        {
             string  userName  =  parameters[ 0 ]  as   string ;
             string  password  =  parameters[ 1 ]  as   string ;

             if  (password  ==   null   ||  password  ==   string .Empty)
                 throw   new  ClientRejectedException( null );

            connection.Client.SetAttribute( " userName " , userName);
             // 获取共享对象(OnLineUsers)
            ISharedObject users_so  =  GetSharedObject(connection.Scope,  " OnLineUsers " );
             if  (users_so  ==   null )
            {
                 // 创建共享对象
                CreateSharedObject(connection.Scope,  " OnLineUsers " ,  false );
                users_so  =  GetSharedObject(connection.Scope,  " OnLineUsers " );
            }
             // 更新共享对象
            users_so.SetAttribute(userName, userName);
             return   true ;
        }

         ///   <summary>
         ///  加入房间
         ///   </summary>
         ///   <param name="client"></param>
         ///   <param name="room"></param>
         ///   <returns></returns>
         public   override   bool  RoomJoin(IClient client, IScope room)
        {
            Trace.WriteLine( " 加入房间  "   +  room.Name);
             return   true ;
        }

         ///   <summary>
         ///  离开房间
         ///   </summary>
         ///   <param name="client"></param>
         ///   <param name="room"></param>
         public   override   void  RoomLeave(IClient client, IScope room)
        {
            Trace.WriteLine( " 离开房间  "   +  room.Name);
             base .RoomLeave(client, room);
        }

         ///   <summary>
         ///  用户退出
         ///   </summary>
         ///   <param name="connection"></param>
         public   override   void  AppDisconnect(IConnection connection)
        {
             string  userName  =  connection.Client.GetAttribute( " userName " )  as   string ;
            ISharedObject users_so  =  GetSharedObject(connection.Scope,  " OnLineUsers " );
             if  (users_so  !=   null )
            {
                 // 从共享对象中移除当前退出系统用户
                users_so.RemoveAttribute(userName);
            }
             base .AppDisconnect(connection);
        }
    }
}

 

      开发好了ApplicationAdapter，还需要对此ApplicationAdapter进行通信配置，在FluorineFx的应用程序目录中添加app.config并进行如下配置：

<? xml version="1.0" encoding="utf-8" ?>
< configuration >
     < application-handler  type ="Fx.Adapter.MyApp" />
</ configuration >

 

      另外还需要配置一个客户端方法的通信通道，通过FluorineFx网站下的WEB-INF/flex/service-config.xml配置：

<?xml version="1.0" encoding="utf-8" ?>
<services-config>

      <channels>

          < channel-definition  id ="my-rtmp"  class ="mx.messaging.channels.RTMPChannel" >
                < endpoint  uri ="rtmp://{server.name}:1617"  class ="flex.messaging.endpoints.RTMPEndpoint" />
          </ channel-definition >

      </channels>

</services-config>

 

      如上便完成了服务器端的开发，在flash/felx客户端通过NetConnection去连接应用，并根据当前的连接去连接服务器端的远程共享对象，最后通过异步事件来实现数据同步更新。如下程序运行截图：

              

 

      此时开多个浏览器窗口测试，不同窗口使用不同的用户名登录，可以很清楚的看到，我们已经实现了在线用户的数据同步功能，可以及时的反映用户上线离线，可以及时的同步在线用户列表的数据。

 

      另外远程共享对象还有一个功能非常强大的特性方法，就是连接到共享对象的客户端之间可以直接广播消息（客户端调用客户端的方法）。就以上面在线用户的案例为例，用户成功登陆服务器我需要广播一条消息，用户退出了我也需要广播一条消息，要实现这个功能就需要通过远程共享的客户端呼叫(send()方法)来实现，如下代码块：

private  function onCallClient(message:String): void
{
    so.send( " onSayMessage " ,message);
}

      

      远程共享对象的send()方法调用了onSayMessage这个客户端方法来实现对连接到共享对象上的所有客户端广播消息，那么我们的在定义一个onSayMessage方法，如下：

/* *
 * 接受客户端呼叫---此方法必须是public修饰
  */
public  function onSayMessage(message:Object): void
{
    traceWriteln(message.toString());
}

private function traceWriteln(param:String):void
{
   txtTraceArea.htmlText += param + "\n";
   txtTraceArea.validateNow();
   txtTraceArea.verticalScrollPosition = txtTraceArea.maxVerticalScrollPosition;
}

 

            

      如果想实现用户退出广播，可以通过服务器端RPC的方法调用客户端的方法来实现，关于RPC请查看《 Flex与.NET互操作(十一)：基于FluorineFx.Net的及时通信应用（Remote Procedure Call）(二) 》有详细介绍。下面是Flex客户端的完整代码：

<? xml version = " 1.0 "  encoding = " utf-8 " ?>
< mx:Application xmlns:mx = " http://www.adobe.com/2006/mxml "  layout = " absolute "   
    width = " 530 "  height = " 378 "  backgroundGradientAlphas = " [1.0, 1.0] "  
    backgroundGradientColors = " [#000000, #686868] "  fontSize = " 12 " >
     < mx:Script >
         <! [CDATA[
            import mx.controls.Alert;
            import dotnet.fluorinefx.VO.UserInfo;
            
             private  var nc:NetConnection;
             private  var so:SharedObject;
             private  var info:UserInfo;
            
             private  function connectionServer( event :MouseEvent): void
            {
                info  =   new  UserInfo();
                info.UserName  =   this .txtUserName.text;
                info.Password  =   this .txtPassword.text;
                
                nc  =   new  NetConnection();
                nc.connect( " rtmp://localhost:1617/SOAPP " ,info.UserName,info.Password);
                nc.addEventListener(NetStatusEvent.NET_STATUS,onStatusHandler);
                nc.client  =   this ;
                
                 this .txtUserName.text = "" ;
                 this .txtPassword.text = "" ;
                 this .txtUserName.setFocus();
            }
            
             private  function onStatusHandler( event :NetStatusEvent): void
            {
                 this .connStatus.text  =   " 连接状态： "   +   event .info.code;
                 if ( event .info.code  ==   " NetConnection.Connect.Success " )
                {
                     // 连接远程共享对象
                    so  =  SharedObject.getRemote( " OnLineUsers " ,nc.uri, false );
                     if (so)
                    {
                        so.addEventListener(SyncEvent.SYNC,onSyncHandler);
                        so.connect(nc);
                        so.client  =   this ;
                    }
                    onCallClient( " 用户【 <font color=\ " #4100b9\ " > " + info.UserName + " </font>】登陆了系统！ " );
                }
            }
            
             private  function onSyncHandler( event :SyncEvent): void
            {
                var temp:Array  =   new  Array();
                 for (var u:String  in  so.data)
                {
                     // traceWriteln("异步事件->共享对象：" + u + ":" + so.data[u]);
                    temp.push(so.data[u]);
                }
                 this .userList.dataProvider  =  temp;
            }
            
             private  function traceWriteln(param:String): void
            {
                txtTraceArea.htmlText  +=  param  +   " \n " ;
                txtTraceArea.validateNow();
                txtTraceArea.verticalScrollPosition  =  txtTraceArea.maxVerticalScrollPosition;
            }
            
             private  function onCallClient(message:String): void
            {
                so.send( " onSayMessage " ,message);
            }
             /* *
             * 接受客户端呼叫
              */
             public  function onSayMessage(message:Object): void
            {
                traceWriteln(message.toString());
            }
        ]] >
     </ mx:Script >
     < mx:Label x = " 24 "  y = " 134 "  id = " connStatus "  width = " 288 "  color = " #FFFFFF " />
     < mx:List x = " 342 "  y = " 10 "  height = " 347 "  width = " 160 "  id = " userList "   >
     </ mx:List >
     < mx:Form x = " 24 "  y = " 10 "  width = " 236 " >
         < mx:FormItem label = " 用户名： "  color = " #FFFFFF " >
             < mx:TextInput id = " txtUserName "  width = " 130 "  color = " #000000 " />
         </ mx:FormItem >
         < mx:FormItem label = " 密  码： "  color = " #FFFFFF " >
             < mx:TextInput id = " txtPassword "  width = " 130 "  
                color = " #000000 "  displayAsPassword = " true " />
         </ mx:FormItem >
         < mx:FormItem label = "" >
             < mx:Button label = " 登陆服务器 "  click = " connectionServer(event) "  
                enabled = " {this.txtUserName.text.length&gt;0?true:false} "  color = " #FFFFFF " />
         </ mx:FormItem >
     </ mx:Form >
     < mx:TextArea x = " 24 "  y = " 174 "  width = " 288 "  height = " 153 "  alpha = " 1.0 "  
        backgroundColor = " #F2D2D2 "  backgroundAlpha = " 0.26 "  color = " #FFFFFF "  
        id = " txtTraceArea "  borderColor = " #FFFFFF " />
</ mx:Application >