随机计时器示例

package {
    import flash.events.TimerEvent;
    import flash.events.TimerEvent;
    import flash.utils.Timer;

    public class RandomTimer extends Timer {

        public var minimumDelay:Number;
        public var maximumDelay:Number;
        private var _count:uint = 0;
        private var _repeatCount:int = 0;

        public function RandomTimer(min:Number, max:Number, repeatCount:int = 0) {
            super(delay, repeatCount);

            minimumDelay = min;
            maximumDelay = max;
            _repeatCount = repeatCount;
        }

        override public function start():void {
            delay = nextDelay();
            addEventListener(TimerEvent.TIMER, timerHandler);
            super.start();
        }

        private function nextDelay():Number {
            return (minimumDelay + (Math.random() * (maximumDelay - minimumDelay)));
        }

        override public function stop():void {
            removeEventListener(TimerEvent.TIMER, timerHandler);
            super.stop();
        }

        protected function timerHandler(event:TimerEvent):void {
            _count++;
            if ((_repeatCount > 0) && (_count >= _repeatCount)) {
                stop();
                dispatchEvent(new TimerEvent(TimerEvent.TIMER_COMPLETE));
            }
            delay = nextDelay();
        }
        
        override public function reset():void {
            _count = 0;
            super.reset();
        }
    }
}

这个 RandomTimer 扩展 Timer，并且使用完全相同，只是它以随机间隔发送。

示例用法，在 1 到 5 秒之间随机调度：

var t:int = getTimer();

var timer:RandomTimer = new RandomTimer(1000, 5000);
timer.addEventListener(TimerEvent.TIMER, timerHandler);
timer.start();

function timerHandler(event:TimerEvent):void {
    trace("Time since last dispatch: " + (getTimer() - t));
    t = getTimer();
}

以上示例将输出：

[trace] Time since last dispatch: 1374
[trace] Time since last dispatch: 2459
[trace] Time since last dispatch: 3582
[trace] Time since last dispatch: 1335
[trace] Time since last dispatch: 4249