FLEX中加载图片失败时自动加载默认图片.

就是使用图片组件的brokenImageSkin 样式，
这个样式非常方便，一般用在产品列表，新品图片没有出来，先用一张缩略的“尚没有展品照片”显示，如果有，就用产品图片自动替换掉这个“尚没有展品照片”的图片。

<? xml version="1.0" ?>
<!--  http://blog.flexexamples.com/2008/03/02/setting-a-custom-broken-image-skin-for-the-image-control-in-flex/  -->
< mx:Application  xmlns:mx ="http://www.adobe.com/2006/mxml"
        layout ="vertical"
        verticalAlign ="middle"
        backgroundColor ="white" >

     < mx:Script >
         <![CDATA[
            import mx.controls.Alert;

            private var alert:Alert;

            private function image_ioError(evt:IOErrorEvent):void {
                alert = Alert.show(evt.text, evt.type);
            }

            private function loadImage(src:String):void {
                image.source = src;
            }
         ]]>
     </ mx:Script >

     < mx:Style >
        Image {
            brokenImageSkin: Embed("assets/flex_logo.jpg");
        }
     </ mx:Style >

     < mx:ApplicationControlBar  dock ="true" >
         < mx:Button  label ="Good"
                click ="loadImage('assets/flashplayer_icon.jpg');"   />
         < mx:Button  label ="Bad"
                click ="loadImage('assets/404.gif');"   />
     </ mx:ApplicationControlBar >

     < mx:Image  id ="image"
            maintainAspectRatio ="true"
            scaleContent ="false"
            width ="200"
            height ="200"
            ioError ="image_ioError(event);"   />

</ mx:Application >

来自： http://blog.flexexamples.com/2008/03/02/setting-a-custom-broken-image-skin-for-the-image-control-in-flex/