Hide navigationbar border

Hide-Navigation-Bar-Border.swift

extension UINavigationController {
    func hideHairline() {
        if let hairline = findHairlineImageViewUnder(navigationBar) {
            hairline.isHidden = true
        }
    }
    func restoreHairline() {
        if let hairline = findHairlineImageViewUnder(navigationBar) {
            hairline.isHidden = false
        }
    }
    func findHairlineImageViewUnder(_ view: UIView) -> UIImageView? {
        if view is UIImageView && view.bounds.size.height <= 1.0 {
            return view as? UIImageView
        }
        for subview in view.subviews {
            if let imageView = self.findHairlineImageViewUnder(subview) {
                return imageView
            }
        }
        return nil
    }
}