Flex表单中回车下移焦点的方法

对于习惯了使用桌面应用程序的用户而言，回车后下移焦点到下一个编辑组件中的小功能，是非常贴心的，利用flex中的KEY_DOWN事件可以方便的实现回车下移焦点，代码如下：
 <?xml version="1.0" encoding="utf-8"?>
<mx:Module xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" creationComplete="CreationComplete()" height="398" width="518" backgroundColor="#E6E3E3">
<mx:Script>
<!--[CDATA[
import mx.containers.HBox;
import mx.core.UIComponent;
import mx.events.CloseEvent;
import mx.controls.Alert;

public function CreationComplete():void{
var monthNames:Array=new Array;
var dayNames:Array=new Array;

monthNames.push("一","二","三","四","五","六","七","八","九","十","十一","十二");
dayNames.push("日","一","二","三","四","五","六");
this.edtccrq.monthNames = monthNames;//中文月份名
this.edtgrrq.monthNames = monthNames;
this.edtrzrq.monthNames = monthNames;
this.edtccrq.dayNames = dayNames;//中文星期名
this.edtgrrq.dayNames = dayNames;
this.edtrzrq.dayNames = dayNames;
this.edtccrq.formatString = "YYYY-MM-DD";//本地日期格式
this.edtgrrq.formatString = "YYYY-MM-DD";;
this.edtrzrq.formatString = "YYYY-MM-DD";


//以下批量添加事件监视
var childs:Array= this.mainvbox.getChildren();
//取出顶级对象的子组件集合
var item:Object;
for each (item in childs){
if (item is HBox){
var items:Array = (item as HBox).getChildren();
//取出HBox中的子组合集合
var subitem:Object;
for each (subitem in items){
if (subitem is UIComponent) {
(subitem as UIComponent).addEventListener(KeyboardEvent.KEY_DOWN,this.onKeyDown);
//给组件注册KEY_DOWN事件。
}
}
}
}
}

private function btncloseclick():void{
this.parentApplication.panelassetedit.visible=false;
this.paren