指示器代码段（2D绘图用于日志记录）

   // 红色指示器

    CAShapeLayer *shapeLayerLine = [CAShapeLayer layer];

    shapeLayerLine.strokeColor = [UIColor redColor].CGColor;

    shapeLayerLine.fillColor = INDICATORCOLOR;

    shapeLayerLine.lineWidth = 1.f;

    shapeLayerLine.lineCap = kCALineCapSquare;

    

    NSUInteger ruleHeight = 20; // 文字高度

    CGMutablePathRef pathLine = CGPathCreateMutable();

    //画笔终点

    CGPathMoveToPoint(pathLine, NULL, self.frame.size.width / 2, self.frame.size.height - DISTANCETOPANDBOTTOM - ruleHeight);

    //画中线

    CGPathAddLineToPoint(pathLine, NULL, self.frame.size.width / 2, DISTANCETOPANDBOTTOM + SHEIGHT);

    //画左侧斜线

    CGPathAddLineToPoint(pathLine, NULL, self.frame.size.width / 2 - SHEIGHT / 2, DISTANCETOPANDBOTTOM);

    //画右侧斜线

    CGPathAddLineToPoint(pathLine, NULL, self.frame.size.width / 2 + SHEIGHT / 2, DISTANCETOPANDBOTTOM);

    //再画一条中线用于覆盖

    CGPathAddLineToPoint(pathLine, NULL, self.frame.size.width / 2, DISTANCETOPANDBOTTOM + SHEIGHT);

    

    shapeLayerLine.path = pathLine;

    [self.layer addSublayer:shapeLayerLine];