flex中用CheckBox作为DataGrideItemRender状态丢失的解决方法

flex中用CheckBox作为DataGrid的DataGrid的ItemRender，当我们滚动DataGrid的滚动条或者我们对DataGrid的列进行排序的时候经常会出现CheckBox的选中状态丢失或者说不及时更新的问题，下面的一个demo解决了这个问题：主要方法是在重写ItemRender的set data方法，在其中对ChexBox进行赋值操作。

 

ItemRenderDemo.mxml:

<?xml version="1.0" encoding="utf-8"?><mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" creationComplete="init()"><mx:Script><!--[CDATA[import mx.collections.ArrayCollection;import mx.controls.CheckBox;private var d:ArrayCollection;private function init():void{d = new ArrayCollection();var xml:XML = <cols><col id="1" v="true" label="选中"/><col id="2" v="false" label="未选中"/><col id="3" v="false" label="未选中"/><col id="4" v="true" label="选中"/><col id="5" v="false" label="未选中"/><col id="6" v="true" label="选中"/><col id="7" v="false" label="未选中"/><col id="8" v="false" label="未选中"/><col id="9" v="true" label="选中"/><col id="10" v="false" label="未选中"/></cols>for each(var col:XML in xml.col){d.addItem(col.copy());}dg.dataProvider = d;this.addEventListener("CHANGE_STATE_EVENT",changeStateEventHandler);}private function changeStateEventHandler(evt:Event):void{evt.stopImmediatePropagation();var cb:CheckBox = evt.target as CheckBox;var xml:XML;var index:int = d.getItemIndex(dg.selectedItem);var id:String = [e-mail]();if(cb.selected){xml = <col id={id} v="true" label="选中"/>}if(!cb.selected){xml = <col id={id} v="false" label="未选中"/>}d.removeItemAt(index);d.addItemAt(xml,index);}]]--></mx:Script><mx:DataGrid x="112" y="94" width="376" height="224" id="dg"><mx:columns><mx:DataGridColumn headerText="Column 1" dataField="@id"/><mx:DataGridColumn headerText="Column 2" dataField="@v" itemRenderer="Render"/><mx:DataGridColumn headerText="Column 3" dataField="@label"/></mx:columns></mx:DataGrid></mx:Application>

 

Render.mxml:

<?xml version="1.0" encoding="utf-8"?><mx:CheckBox xmlns:mx="http://www.adobe.com/2006/mxml" change="changeHandler()"><mx:Script><!--[CDATA[[Bindable]private var isSelected:Boolean;override public function get data():Object{return super.data;}override public function set data(value:Object):void{super.data = value;if(value.@v == "true"){isSelected = true;}else if(value.@v == "false"){isSelected = false;}else{trace("some error hannped");}this.selected = isSelected;}private function changeHandler():void{dispatchEvent(new Event("CHANGE_STATE_EVENT",true,false));}]]--></mx:Script></mx:CheckBox>