Flex 4 DropDownList

Flex 4 DropDownList:
<?xml version="1.0" encoding="utf-8"?>
<!-- Simple example to demonstrate the Spark DropDownList control -->
<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">

<fx:Script>
<!--[CDATA[
import mx.collections.ArrayCollection;
import spark.events.IndexChangeEvent;

[Bindable]
public var myDP:ArrayCollection = new ArrayCollection(
[ {product:"Flex", price:100},
{product:"Air", price:200},
{product:"Catalyst", price:300},
{product:"FlashBuilder", price:400} ]);

private function updateSelection(e:IndexChangeEvent):void
{
currSel.text = "Current Product = " + myDDL.selectedItem.product;
currPrc.text = "Price = $" + myDDL.selectedItem.price;
}
]]>
</fx:Script>

<s:Panel width="75%" height="75%" title="My DropDownList Example"
horizontalCenter="0" verticalCenter="0">

<s:VGroup left="10" right="10" top="10" bottom="10">

<!-- Text components used to display current selection and price -->
<s:Label id="currSel" text="Current Product = -"/>
<s:Label id="currPrc" text="Price = $ -"/>

<!-- DropDownList will call the updateSelection function when the
selectionChanged event is dispatched -->
<s:DropDownList id="myDDL" prompt="Select One"
width="200" dataProvider="{myDP}"
labelField="product"
change="updateSelection(event);"/>

</s:VGroup>
</s:Panel>
</s:Application>
DropDownList 动态定位
从remote取回数据后，动态定位到
<?xml version="1.0" encoding="utf-8"?>
<!-- Simple example to demonstrate the Spark DropDownList control -->
<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"