remove 1px bottom line of the navigation bar

remove-bottom-line-navbar.md

If you just want to use a solid navigation bar color and have set this up in your storyboard, use this code in your AppDelegate class to remove the 1 pixel border via the appearance proxy:

Objective-C

[[UINavigationBar appearance] setBackgroundImage:[[UIImage alloc] init]
                                  forBarPosition:UIBarPositionAny
                                      barMetrics:UIBarMetricsDefault];

[[UINavigationBar appearance] setShadowImage:[[UIImage alloc] init]];

Swift 3.x

        UINavigationBar.appearance().shadowImage = UIImage()
        UINavigationBar.appearance().setBackgroundImage(UIImage(), for: .default)

NOTE: must set isTransluscent UINavigationBar instance to false to avoid transparent navigation bar; either in storyboard or in code

navigationController?.navigationBar.isTranslucent = false

// or

navigationBar.isTranslucent = false

@Cyanide7523 should do it for youself.navigationBar.shadowImage = UIImage()

The problem with this method is that. The 1px points disappears but flickers later.
To reproduce : Set navigation bar to a color and set the ViewController background as the same color.
Make app go to background, open from background. The 1px point line will flicker.

Try navigationBar.setValue(true, forKey: "hidesShadow")

iOS 15:

Note: If you have any scrollable content (scroll view, table view) in your view controller beware of the new behaviour which comes with scrollEdgeAppearance introduced in iOS 15. This appearance by default produces a transparent background, to all navigation bars. The background is controlled by when your scroll view scrolls content behind the navigation bar.

To avoid having transparent nav bars on your screens and still be able to remove the bottom line, use:

func configureScrollEdgeAppearance() {
        if #available(iOS 15, *) {
            guard let navigationBar = navigationController?.navigationBar else { return }

            let appearance = UINavigationBarAppearance()
            appearance.configureWithOpaqueBackground() // use `configureWithTransparentBackground` for transparent background
            appearance.backgroundColor = <your-background-color>
            appearance.shadowColor = .clear
            appearance.shadowImage = UIImage()

            navigationBar.standardAppearance = appearance
            navigationBar.scrollEdgeAppearance = navigationBar.standardAppearance
        }
    }