Flex中通过verticalScrollPosition和maxVerticalScrollPosition

接下来的例子演示了Flex中如何通过verticalScrollPosition和maxVerticalScrollPosition属性，TextArea增加新内容的时候自动滚动，textArea.validateNow()，加载到缓存中，刷新让组件及时正常显示。

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让我们先来看一下代码：

<?xml version="1.0" encoding="utf-8"?>      
<mx:Application name="TextArea_maxVerticalScrollPosition_text"      
        xmlns:mx="http://www.adobe.com/2006/mxml"      
        layout="vertical"      
        verticalAlign="middle"      
        backgroundColor="white"      
        creationComplete="init();">      
       
    <mx:Script>      
        <![CDATA[      
            private var timer:Timer;      
       
            private function init():void            {      
                timer = new Timer(500);      
                timer.addEventListener(TimerEvent.TIMER,onTimer);      
                timer.start();      
            }      
       
            private function onTimer(evt:TimerEvent):void            {      
                var now:String = new Date().toTimeString();      
                var str:String = "[" + timer.currentCount + "] " + now;      
                textArea.text += str + "n";      
                textArea.validateNow();      
                textAreatextAreatextArea.verticalScrollPosition =textArea.maxVerticalScrollPosition;                  }      
        ]]>      
    </mx:Script>      
       
    <mx:TextArea id="textArea"      
            width="200"      
            height="160" />      
       
</mx:Application>