panel隐藏或显示的特效

<?xml version="1.0" encoding="utf-8"?> 
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" 
        layout="vertical" 
        verticalAlign="middle" 
        backgroundColor="white"> 
  
    <mx:Zoom id="zoom" /> 
  
    <mx:ApplicationControlBar dock="true"> 
        <mx:Button label="hide" 
                click="panel.visible = false;" 
                enabled="{panel.visible}" /> 
        <mx:Button label="show" 
                click="panel.visible = true;" 
                enabled="{!panel.visible}" /> 
    </mx:ApplicationControlBar> 
  
    <mx:Panel id="panel" 
            title="title" 
            status="status" 
            showEffect="{zoom}" 
            hideEffect="{zoom}" 
            width="100%" 
            height="100%"> 
  
        <mx:ControlBar> 
            <mx:Label text="control bar" /> 
        </mx:ControlBar> 
    </mx:Panel> 
  
</mx:Application>