使用NumberFormatter判断TextInput输入内容是否为数字，如果是则格式化数字。

NumberFormatter标签学习.
示例：

代码：

<? xml version="1.0" ?>
<!--  Simple example to demonstrate NumberFormatter.  -->
< mx:Application  xmlns:mx ="http://www.adobe.com/2006/mxml" >

     < mx:Script >
         <![CDATA[

          import mx.events.ValidationResultEvent;
          private var vResult:ValidationResultEvent;

          // Event handler to validate and format input.
          private function Format():void
          {
             vResult = numVal.validate();
             if (vResult.type==ValidationResultEvent.VALID) {

                formattedNumber.text= numberFormatter.format(inputVal.text);
             }

             else {
                formattedNumber.text= "";
             }
          }
       ]]>
     </ mx:Script >

     < mx:NumberFormatter  id ="numberFormatter"  precision ="4"
        useThousandsSeparator ="true"  useNegativeSign ="true" />

     < mx:NumberValidator  id ="numVal"  source =" {inputVal} "  property ="text"
        allowNegative ="true"  domain ="real" />

     < mx:Panel  title ="NumberFormatter Example"  width ="75%"  height ="75%"
            paddingTop ="10"  paddingLeft ="10"  paddingRight ="10"  paddingBottom ="10" >

         < mx:Form >
             < mx:FormItem  label ="Enter number:" >
                 < mx:TextInput  id ="inputVal"  text =""  width ="50%" />
             </ mx:FormItem >

             < mx:FormItem  label ="Formatted number (precision=4): " >
                 < mx:TextInput  id ="formattedNumber"  editable ="false"  width ="50%" />
             </ mx:FormItem >

             < mx:FormItem >
                 < mx:Button  label ="Validate and Format"  click ="Format();" />
             </ mx:FormItem >
         </ mx:Form >

     </ mx:Panel >
</ mx:Application >

点击查看源文件

来自： http://www.flex-tutorial.fr/2008/05/18/flex-formatter-exemple-de-numberformatter-en-mxml-et-actionscript/