Flex中改变一个modal Alert控件模糊度，透明度以及其颜色的例子

<?xml version="1.0" encoding="utf-8"?> 
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" 
        layout="vertical" 
        verticalAlign="middle" 
        backgroundColor="white" 
        creationComplete="showAlert()"> 
  
    <mx:Style> 
        Alert { 
            modalTransparencyBlur: 5; 
            modalTransparency: 0.6; 
            modalTransparencyColor: #FF0000; 
            modalTransparencyDuration: 1000; 
        } 
    </mx:Style> 
  
    <mx:Script> 
        <![CDATA[ 
            import mx.controls.Alert; 
  
            private var a:Alert; 
  
            private function showAlert():void { 
                a = Alert.show("text", "title", Alert.OK); 
            } 
        ]]> 
    </mx:Script> 
  
    <mx:Button label="Show Alert" click="showAlert()" /> 
  
</mx:Application>