如何在IList Dataprovider中向DataGroup發送有關數據更改的信號？

我實現IList接口像如何在IList Dataprovider中向DataGroup發送有關數據更改的信號？

[Bindable] 
    public class MemList implements IList 
    { 
    public function MemList() 
    {  
    }  
    public function get length():int 
    { 
     var size:int = 5000; 
     return size;  
    }  
    public function addItem(item:Object):void 
    { 
    }  
    public function addItemAt(item:Object, index:int):void 
    {  
    }  
    public function getItemAt(index:int, prefetch:int=0):Object 
    {  
     var obj:Object = new Object();      
     obj.value = ByteStr(); // this function return a string 
     return obj;  
    }  
    public function getItemIndex(item:Object):int 
    {  
     return 0; 
    }  
    public function itemUpdated(item:Object, property:Object=null, oldValue:Object=null, newValue:Object=null):void 
    {  
    }  
    public function removeAll():void 
    {  
    }  
    public function removeItemAt(index:int):Object 
    {  
     return null; 
    }  
    public function setItemAt(item:Object, index:int):Object 
    {  
     return null; 
    }  
    public function toArray():Array 
    {  
     return null; 
    }  
    public function addEventListener(type:String, listener:Function, useCapture:Boolean=false, priority:int=0, useWeakReference:Boolean=false):void 
    { 
    }  
    public function removeEventListener(type:String, listener:Function, useCapture:Boolean=false):void 
    { 
    }  
    public function dispatchEvent(event:Event):Boolean 
    { 
     return false; 
    }  
    public function hasEventListener(type:String):Boolean 
    { 
     return false; 
    }  
    public function willTrigger(type:String):Boolean 
    { 
     return false; 
    } 
    }

，並DATAGROUP提供其對象作爲數據提供者，在MXML文件我這樣做

<fx:Script><![CDATA[ 

    [Bindable]private var list:MemList = new MemList(); 

    protected function onBtnShow(event:MouseEvent):void 
    {   
     send(somenumber, MAX_SIZE, onShowResp);//get data from network  
    } 

    private function onShowResp(retVal:uint, ba:ByteArray):void 
    { 
     //this function called when ba bytearray is filled with data. 
    }   

    ]]></fx:Script> 
<s:Button id="btnShow" label="Show" click="onBtnShow(event)"/> 
<s:Scroller verticalScrollPolicy="auto" id="aScroller" 
     liveScrolling="false"> 
     <s:DataGroup id="dgMemView" width="100%" height="350"   
      dataProvider="{list}" 
      clipAndEnableScrolling="true" 
      itemRenderer="ItemRenderer" 
      >   
      <s:layout> 
      <s:VerticalLayout useVirtualLayout="true"/> 
      </s:layout>   
     </s:DataGroup> 
     </s:Scroller> 

public function ByteStr(loc:uint):String 
    { 
     //this function can access ba bytearray filled with data. do some processing 
     on that data and return a string. 
     return string; 
    }

我的問題是，當應用程序運行數據組不顯示任何東西因爲在ba（bytearray）中沒有必須填充網絡數據的數據。當我按下顯示按鈕時，它發出一個請求並用數據填充ba（bytearray）。我如何通知Datagroup數據已更改。我正在使用Flash Builder 4.5。謝謝

來源

2013-03-15 Sarfraz Ahmed