flex 4 运行时改变显示层次.类似z轴功能.

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600">
<s:layout>
<s:BasicLayout/>
</s:layout>
<fx:Script>
<!--[CDATA[
import mx.core.IVisualElement;
protected function mouseOverHandler(event:MouseEvent):void
{
this.setElementIndex(event.currentTarget as IVisualElement,this.numElements-1);
}
]]-->
</fx:Script>
<mx:DateChooser x="469" y="195" mouseOver="mouseOverHandler(event)"/>
<mx:DateChooser x="346" y="188" mouseOver="mouseOverHandler(event)"/>
</s:Application>