使用三角函数让sprite绕圆形移动

private var _square:Sprite;
  private var _angle:uint;
  
  public function flashtest()
  {
   _square = new Sprite();
   _square.graphics.lineStyle(0.5);
   _square.graphics.drawCircle(0,0,20);
   addChild(_square);
   _angle = 0;
   addEventListener(Event.ENTER_FRAME,move);
  }
  private function move(event:Event):void
  {
   var converter:Converter = Unit.DEGREE.getConverterTo(Unit.RADIAN);
   var angleRadians:Number = converter.convert(_angle);
   _square.x = Math.cos(angleRadians) * 100 + 200;
   _square.y = Math.sin(angleRadians) * 100 + 200;
   _angle++;
  }