Flex 默认选中textInput的值

请问大家，如何实现    默认选中textInput控件的值，当该控件得到焦点时，值消失！  在线等。。。。

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没明白

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这个过程很快的，你看不到

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你可以参考一下
<?xml version="1.0" encoding="utf-8"?>
<mx:WindowedApplication xmlns:mx="http://www.adobe.com/2006/mxml"
layout="vertical" initialize="init()">
<mx:Script>
<![CDATA[
import mx.controls.Alert;
private function init():void{
this.focusManager.setFocus(TI1);
TI1.focusManager.showFocus();
//Alert.buttonWidth = 150;
//Alert.buttonHeight = 50;
//Alert.show("test");
}
]]>
</mx:Script>
<mx:Button label="test" id="b1"/>
<mx:TextInput id="TI1"  />
<mx:Button label="test2"/>
</mx:WindowedApplication>

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XML code:

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" creationComplete="init()">
<mx:Script>
<![CDATA[
import mx.controls.Alert;
private function init():void{