Question

如何隐藏UINavigationbar下面的黑线，swift版

Answer 1

先建一个UIBarExtension.swift的文件来扩展UINavigationBar
import Foundation
import UIKit

extension UINavigationBar {

func hideBottomHairline() {
let navigationBarImageView = hairlineImageViewInNavigationBar(self)
navigationBarImageView!.hidden = true
}

func showBottomHairline() {
let navigationBarImageView = hairlineImageViewInNavigationBar(self)
navigationBarImageView!.hidden = false
}

private func hairlineImageViewInNavigationBar(view: UIView) -> UIImageView? {
if view.isKindOfClass(UIImageView) && view.bounds.height <= 1.0 {
return (view as UIImageView)
}

let subviews = (view.subviews as [UIView])
for subview: UIView in subviews {
if let imageView: UIImageView = hairlineImageViewInNavigationBar(subview)? {
return imageView
}
}

return nil
}

}

extension UIToolbar {

func hideHairline() {
let navigationBarImageView = hairlineImageViewInToolbar(self)
navigationBarImageView!.hidden = true
}

func showHairline() {
let navigationBarImageView = hairlineImageViewInToolbar(self)
navigationBarImageView!.hidden = false
}

private func hairlineImageViewInToolbar(view: UIView) -> UIImageView? {
if view.isKindOfClass(UIImageView) && view.bounds.height <= 1.0 {
return (view as UIImageView)
}

let subviews = (view.subviews as [UIView])
for subview: UIView in subviews {
if let imageView: UIImageView = hairlineImageViewInToolbar(subview)? {
return imageView
}
}

return nil
}

}

再在viewDidLoad里使用
let navigationBar = self.navigationController?.navigationBar
navigationBar?.hideBottomHairline()