iOS 中添加虚线框

(```)

• (void)backGroundViewLine:(CGFloat)lineWidth lineColor:(UIColor *)lineColor {
  CAShapeLayer *border = [CAShapeLayer layer];
  border.strokeColor = lineColor.CGColor;
  border.cornerRadius = 4.0;
  border.fillColor = nil;
  border.path = [UIBezierPath bezierPathWithRect:self.backGroundView.bounds].CGPath;
  border.frame = self.backGroundView.bounds;
  border.lineWidth = lineWidth;
  border.lineDashPattern = @[@(1), @(2)];
  [self.backGroundView.layer addSublayer:border];
  }
  (```)