这可能听起来很愚蠢，但这个发际线只在viewController视图的背景色被设置为任何颜色时出现，除了白色。得知这个事实我很震惊。

如果你想让它毫不费力地消失只要设置控制器视图背景色为WHITE color。

在Swift 3.0中

编辑你的AppDelegate.swift通过添加以下代码到你的应用程序函数:

// Override point for customization after application launch.

// Remove border in navigationBar
UINavigationBar.appearance().shadowImage = UIImage()
UINavigationBar.appearance().setBackgroundImage(UIImage(), for: .default)

在子视图中找到发际线的一个很好的简短Swift函数是:

 func findHairLineInImageViewUnder(view view: UIView) -> UIImageView? {
    if let hairLineView = view as? UIImageView where hairLineView.bounds.size.height <= 1.0 {
        return hairLineView
    }

    if let hairLineView = view.subviews.flatMap({self.findHairLineInImageViewUnder(view: $0)}).first {
      return hairLineView
    }

    return nil
}

这里有一个非常简单的解决方案:

self.navigationController.navigationBar.clipsToBounds = YES;

适用于iOS 13+

窍门是用透明背景初始化'UINavigationBarAppearance'。然后，您可以轻松地删除导航栏的水平线。

let appearance = UINavigationBarAppearance()
appearance.configureWithTransparentBackground()
appearance.backgroundColor = .green // Required background color

最后，按照apple的建议将外观更改添加到导航项中。

self.navigationItem.standardAppearance = appearance
self.navigationItem.scrollEdgeAppearance = appearance
self.navigationItem.compactAppearance = appearance

我刚刚为这个创建了一个扩展…关于格式的问题很抱歉(这是我的第一个答案)。

用法:

  override func viewDidLoad() {
    super.viewDidLoad()
    self.navigationController?.hideShadow = true
}

扩展:

 UINavigationController.swift
//  Created by Ricardo López Rey on 16/7/15.

import Foundation


struct UINavigationControllerExtension {
    static var hideShadowKey : String = "HideShadow"
static let backColor = UIColor(red: 247/255, green: 247/255, blue: 248/255, alpha: 1.0)
}

extension UINavigationController {

    var hideShadow : Bool {
        get {
            if let ret =  objc_getAssociatedObject(self, &UINavigationControllerExtension.hideShadowKey) as? Bool {
                return ret
            } else {
                return false
            }


        }
        set {
            objc_setAssociatedObject(self,&UINavigationControllerExtension.hideShadowKey,newValue, objc_AssociationPolicy(OBJC_ASSOCIATION_RETAIN_NONATOMIC))

            if newValue {


            self.navigationBar.setBackgroundImage(solidImage(UINavigationControllerExtension.backColor), forBarMetrics: UIBarMetrics.Default)

                self.navigationBar.shadowImage = solidImage(UIColor.clearColor())
            } else {
                self.navigationBar.setBackgroundImage(nil, forBarMetrics: UIBarMetrics.Default)
            }
        }
    }

    private func solidImage(color: UIColor, size: CGSize = CGSize(width: 1,height: 1)) -> UIImage {
        var rect = CGRectMake(0, 0, size.width, size.height)
        UIGraphicsBeginImageContextWithOptions(size, false, 0)
        color.setFill()
        UIRectFill(rect)
        var image: UIImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }


}