private var size:uint         = 80;
        private var bgColor:uint      = 0xFF0000;
        private var borderColor:uint  = 0x00FF00;
        private var borderAlpha:Number = 0.2 // 线条的alpha值，0.0-1.0
        private var borderSize:uint   = 3; //线条的粗细,0-255
          
        public function CircleShape()
        {
            var child:Shape = new Shape();
            var halfSize:uint = Math.round(size / 2);
            child.graphics.beginFill(bgColor, 0.5); //背景颜色,alpha值
            child.graphics.lineStyle(borderSize, borderColor, borderAlpha); //指定一种线条样式，Flash 可将该样式用于随后调用对象的其它 Graphics 方法（如 lineTo() 或 drawCircle()）。
            child.graphics.drawCircle(halfSize, halfSize, halfSize); //绘制，x,y坐标,半径
            child.graphics.endFill(); //对从上一次调用 beginFill() 方法之后添加的直线和曲线应用填充
            addChild(child);   
        }