<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/06/29/setting-a-complete-effect-on-an-image-control-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:Script>
        <![CDATA[
            private function button_click(evt:MouseEvent):void {
                image.load("assets/Fx.png");
            }
        ]]>
    </mx:Script>

    <mx:ApplicationControlBar dock="true">
        <mx:Button id="button"
                label="Load Image"
                click="button_click(event);" />
    </mx:ApplicationControlBar>

    <mx:Image id="image"
            completeEffect="Fade"
            maintainAspectRatio="true"
            width="100%"
            height="100%" />

</mx:Application>

或者用AS实现（1）

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/06/29/setting-a-complete-effect-on-an-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.effects.*;

            private function init():void {
                image.setStyle("completeEffect", Fade);
            }

            private function button_click(evt:MouseEvent):void {
                image.load("assets/Fx.png");
            }
        ]]>
    </mx:Script>

    <mx:ApplicationControlBar dock="true">
        <mx:Button id="button"
                label="Load Image"
                click="button_click(event);" />
    </mx:ApplicationControlBar>

    <mx:Image id="image"
            maintainAspectRatio="true"
            width="100%"
            height="100%"
            initialize="init();" />

</mx:Application>
（2）
 
<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/06/29/setting-a-complete-effect-on-an-image-control-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white"
        initialize="init();">

    <mx:Script>
        <![CDATA[
            import mx.containers.ApplicationControlBar;
            import mx.controls.Button;
            import mx.controls.Image;
            import mx.effects.*;

            private var button:Button;
            private var image:Image;

            private function init():void {
                button = new Button();
                button.label = "Load Image";
                button.addEventListener(MouseEvent.CLICK, button_click);

                var appControlBar:ApplicationControlBar;
                appControlBar = new ApplicationControlBar();
                appControlBar.dock = true;
                appControlBar.addChild(button);
                Application.application.addChildAt(appControlBar, 0);

                image = new Image();
                image.maintainAspectRatio = true;
                image.percentWidth = 100;
                image.percentHeight = 100;
                image.setStyle("completeEffect", Fade);
                addChild(image);
            }

            private function button_click(evt:MouseEvent):void {
                image.load("assets/Fx.png");
            }
        ]]>
    </mx:Script>

</mx:Application>