ASFps类是一个可以在运行时模拟改变影片的帧率的包装类

ASFps.initialize(wiyi_mc);//为wiyi_mc附加帧率属性
wiyi_mc._fps=10;                            //将wiyi_mc的帧率设置为10,此后wiyi_mc._fps将以10帧每秒的帧率播放
wiyi_mc._fps="default";       //将wiyi_mc的帧率恢复为默认的30帧每秒。
wiyi_mc._fps=-20;                         //将wiyi_mc的帧率设置为-20,此后wiyi_mc._fps将以20帧每秒的帧率倒序播放
wiyi_mc._fps=0;                               //将wiyi_mc的帧率恢复为默认的30帧每秒的又一种方法。

*/
class ASFps {
   private var __fps;
   public var _fps;
   var __fpsIntervalID:Number;
   static function next(mc:MovieClip, direction:Number) {
      var d = (direction>0 ? Math.ceil(direction) : Math.floor(direction));
      var c = (mc._currentframe+d)%mc._totalframes;
      (c == 0 ? c=mc._totalframes : null);
      mc.gotoAndStop(c);
      trace(c);
      updateAfterEvent();
   }
   function setFps(fps) {
      if (fps == "default" || fps == 0) {
         this.__fps = fps;
         clearInterval(this.__fpsIntervalID);
      } else if (typeof (fps) == "number") {
         //
         if (this.__fps == fps) {
            return;
         }
         trace("ID:"+this.__fpsIntervalID);
         this.__fps = fps;
         var direction = (fps>0 ? 1 : -1);
         var f = Math.abs(fps);
         if (this.__fpsIntervalID != undefined) {
            clearInterval(this.__fpsIntervalID);
         }
         this.__fpsIntervalID = setInterval(ASFps.next, 1000/f, this, direction);
      }
   }
   function getFps() {
      return this.__fps;
   }
   private function ASFps() {
   }
   static function initialize(mc:MovieClip) {
      if (mc.setFps == undefined) {
         mc.__fps = 0;
         mc.__fpsIntervalID = undefined;
         mc.getFps = ASFps.prototype.getFps;
         mc.setFps = ASFps.prototype.setFps;
         mc.addProperty("_fps", mc.getFps, mc.setFps);
         _global.ASSetPropFlags(mc, "setFps,getFps", 7, 1);
         _global.ASSetPropFlags(mc, "__fps,__fpsIntervalID", 1, 1);
      }
   }
}