[Flex] flex计时器的使用(timer)

用timer可以达到很多功能，定时调用函数，模拟时钟走等等。

定时调用函数：

             var myTimer:Timer = new Timer(50, 1);                                    //设定50毫秒，每次走一毫秒
             myTimer.addEventListener(TimerEvent.TIMER_COMPLETE, handle); //到达计时器终点时调用这个函数
             myTimer.start();

            private function readPreAnswer( evt:TimerEvent ):void
            {

                       Alert.show("Time reach to this function.");

             }

计时功能：

  private var hour_timer:Number=0;
  private var minute_timer:Number=0;
  private var second_timer:Number=0;

 private var handleTimer:Timer;

 private var currentHours:String;

public function timerInit():void
   {
         this.hour_timer = Number("2");
         this.minute_timer = Number("00");
         this.second_timer = Number("00");

          handInTimer = new Timer( 1000 );
          handInTimer.addEventListener( "timer" , timerHandler);
          handInTimer.start();
   }

   private function timerHandler(event:TimerEvent):void
   {
         second_timer--;
         if (second_timer<0){second_timer=59;minute_timer--;}
          if (minute_timer<0){minute_timer=59;hour_timer--;}
          currentHours="0"+String(hour_timer)+":";
          if (minute_timer<10){currentHours+="0"+String(minute_timer)+":";}else{currentHours+=String(minute_timer)+":";}
          if (second_timer<10){currentHours+="0"+String(second_timer);}else{currentHours+=String(second_timer);}
   }

currentHour即会随着时间的推移开始从2:00:00倒数，要想让计时停止，只要调用handInTimer.stop()即可。