图片渐变

<?xml version='1.0' encoding='UTF-8'?>
<!-- Simple example to demonstrate the Spark HSlider 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">
 
 <!-- Panel used as a container for Spark HSlider control examples -->
 <s:Panel title="Spark HSlider Control Example"
    width="75%" height="75%"
    horizontalCenter="0" verticalCenter="0">
  
  <s:VGroup left="10" right="10" top="10" bottom="10">
   <s:HGroup>
    <mx:Spacer width="100" />
    <mx:Image id="fxImage" source="@Embed('2.jpg')"/>
   </s:HGroup>
   
   <s:Label width="100%" text="Drag the slider to change the image transparency"/>
   
   <s:HSlider id="hSlider" minimum="0" maximum="1" value="1" stepSize="0.1"
        snapInterval="0.1" liveDragging="true" change="fxImage.alpha=hSlider.value;"/>
  </s:VGroup>
 </s:Panel>
 
</s:Application>