flex倒计时

在web开发中，倒计时随处可见，这里主要是用到了timer类，比较简单，直接上例子。

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
               xmlns:s="library://ns.adobe.com/flex/spark" 
               xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600" contentCreationComplete="init()">
    
    <fx:Script>
        <![CDATA[
            import flash.events.TimerEvent;
            import flash.events.Event;
            import flash.utils.Timer;
            
            private var timer:Timer;
            private var h_num:int;
            private var m_num:int;
            private var s_num:int;
            private function init():void
            {
                //设置时间
                h_num = 0;
                m_num = 2;
                s_num = 30;
                
                time2_txt.text = time_txt.text = "00:02:30";
                //启动倒计时
                timer = new Timer(1000, 0);
                timer.addEventListener(TimerEvent.TIMER, onTimer);
                timer.start();
            }
            
            private function onTimer(event:TimerEvent):void
            {
                s_num = s_num - 1;
                
                if ((s_num == -1) && (m_num > 0))
                {
                    m_num = m_num - 1;
                    s_num = 59;
                }
                if ((m_num == 0) && (h_num > 0))
                {
                    h_num = h_num -1;
                    m_num = 59;
                    s_num = 59;
                }
                if (s_num < 0)            //时间停止
                {
                    s_num = 0;
                    timer.stop();
                }
                var hh:String;
                var mm:String;
                var ss:String;
                hh = (h_num < 10) ? "0" + h_num.toString() : h_num.toString();
                mm =  (m_num < 10) ? "0" + m_num.toString() : m_num.toString();
                ss = (s_num < 10) ? "0" + s_num.toString() : s_num.toString();
                time2_txt.text = time_txt.text = hh + ":" + mm + ":" + ss;
            }
        ]]>
    </fx:Script>
    
    <fx:Declarations>
        <!-- 将非可视元素（例如服务、值对象）放在此处 -->
    </fx:Declarations>
    <mx:Text id="time2_txt" width="180" height="40" fontSize="38" fontWeight="bold" x="42" y="31"/>
    <mx:Text id="time_txt" width="180" height="40" fontSize="38" color="0xFF0000" fontWeight="bold" x="40" y="29"/>
</s:Application>