Flex itemRenderer渲染器

<?xml version="1.0" encoding="utf-8"?>  
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">  
    <mx:DataGrid x="66.5" y="145" id="dataGrid" dataProvider="{dataXml.children()}">  
        <mx:columns>  
            <mx:DataGridColumn headerText="标签" dataField="@label"/>  
            <mx:DataGridColumn headerText="值" dataField="@value">  
                <mx:itemRenderer>  
                    <mx:Component>  
                        <mx:VBox>  
                         <mx:Script>
                            <![CDATA[
                            [Bindable]  
                                    public var comboSource:Array=["true","false","zhongli"];  
                                    /**初始化下拉框渲染器**/ 
                                    private function init():void 
                                    {  
                                        trace(data.@value);  
                                        if(data.@value=="true")  
                                        {  
                                            comboItem.selectedIndex=0;  
                                        }  
                                        else  if(data.@value=="false")
                                        {  
                                            comboItem.selectedIndex=1;  
                                        }  
                                        else{
                                         comboItem.selectedIndex=3;  
                                        }
                                    }  
                                      
                                    private function onComboClosed():void 
                                    {  
                                        data.@value=comboItem.text;  
                                    }   
                            ]]>
                        </mx:Script>
                            <mx:ComboBox dataProvider="{comboSource}" editable="true" creationComplete="init();" id="comboItem" close="onComboClosed();"/>  
                        </mx:VBox>  
                    </mx:Component>  
                </mx:itemRenderer>  
            </mx:DataGridColumn>  
        </mx:columns>  
    </mx:DataGrid>  
    <mx:Script>
        <![CDATA[
            import mx.controls.Alert;  
            [Bindable]  
            protected var dataXml:XML=<info>  
                <aa label="24" value="false"/>  
                <aa label="55" value="false"/>  
                <aa label="23" value="true"/>  
                <bb label="bb" value="false"/>  
                <bb label="b1" value="zhongli"/>  
            </info>;  
              
            private function onButtonClicked():void 
            {  
                Alert.show(dataXml.toXMLString(),"datasource");  
            }

        ]]>
    </mx:Script>
    <mx:Button x="66" y="115" label="Button" click="onButtonClicked()"/>  
      
</mx:Application>