我正在使用CGMutablePath绘制wifi徽标。当我使用addArc(center:radius:startAngle:endAngle:clockwise:transform:)绘制第二个圆弧时,它将自动绘制一条类似于文档指定的If the path already contains a subpath, this method adds a line connecting the current point to the starting point of the arc.的直线。没有这条线我怎么画呢?谢谢