改变tooltip的最大宽度

<?xml version="1.0" encoding="utf-8"?> 
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" 
        layout="vertical" 
        verticalAlign="middle" 
        backgroundColor="white"> 
  
    <mx:Script> 
        <![CDATA[ 
            import mx.controls.ToolTip; 
        ]]> 
    </mx:Script> 
  
    <mx:ApplicationControlBar dock="true"> 
        <mx:Label text="ToolTip.maxWidth:" /> 
        <mx:HSlider id="slider" 
                minimum="50" 
                maximum="300" 
                value="{ToolTip.maxWidth}" 
                liveDragging="true" 
                snapInterval="5" 
                tickInterval="10" 
                dataTipPrecision="0" 
                change="ToolTip.maxWidth = slider.value" /> 
        <mx:Label text="{slider.value}" /> 
    </mx:ApplicationControlBar> 
  
    <mx:Button label="Roll over to see tool tip" 
            toolTip="The quick brown fox jumped over the lazy dog." /> 
  
</mx:Application>