Flex中如何利用FocusManager类的setFocus函数，设置TextInput的焦点

main.mxml

<?xml version="1.0" encoding="utf-8"?>

<mx:Application name="FocusManager_setFocus_test"

xmlns:mx="http://www.adobe.com/2006/mxml"

layout="vertical"

verticalAlign="middle"

backgroundColor="white">



<mx:Script>

<![CDATA[

import mx.controls.Alert;



private function submitButton_click(evt:MouseEvent):void {

Alert.show(evt.currentTarget.label,

Object(focusManager.getFocus()).name);

}



private function resetButton_click(evt:MouseEvent):void {

username.text = "";

password.text = "";

Alert.show(evt.currentTarget.label,

Object(focusManager.getFocus()).name);

}

]]>

</mx:Script>



<mx:ApplicationControlBar dock="true">

<mx:Button label="Set focus to Username"

click="focusManager.setFocus(username);" />

<mx:Button label="Set focus to Password"

click="focusManager.setFocus(password);" />

</mx:ApplicationControlBar>



<mx:Form id="form"

defaultButton="{submitButton}">

<mx:FormItem label="Username:">

<mx:TextInput id="username" />

</mx:FormItem>

<mx:FormItem label="Password:">

<mx:TextInput id="password"

displayAsPassword="true" />

</mx:FormItem>

<mx:FormItem direction="horizontal"

horizontalAlign="right"

width="100%">

<mx:Button id="submitButton"

label="Submit"

click="submitButton_click(event);" />

<mx:Button id="resetButton"

label="Reset"

click="resetButton_click(event);" />

</mx:FormItem>

</mx:Form>



</mx:Application>