ios开发去除navigationBar下面的横线

 fileprivate func hideBottonLine(views:Array<UIView>){
        for i in 0..<views.count
        {
            let view:UIView = views[i]
            if view.height < 1 {
                view.isHidden = true
            }else if view.subviews.count > 0 {
                hideBottonLine(views: view.subviews)
            }else if view.subviews.count == 0{
                return
            }
        }
    }

调用

hideBottonLine(views: (self.navigationController?.navigationBar.subviews)!)