How to hide UINavigationBar 1px bottom line

Question

I have an app that sometimes needs its navigation bar to blend in with the content.

Does anyone know how to get rid of or to change color of this annoying little bar?

On the image below situation i have - i'm talking about this 1px height line below "Root View Controller"

Answer 1

Wanted to add the Swift version of Serhii's answer. I created a UIBarExtension.swift with the following:

import Foundation
import UIKit

extension UINavigationBar {
    func hideBottomHairline() {
        self.hairlineImageView?.isHidden = true
    }

    func showBottomHairline() {
        self.hairlineImageView?.isHidden = false
    }
}

extension UIToolbar {
    func hideBottomHairline() {
        self.hairlineImageView?.isHidden = true
    }

    func showBottomHairline() {
        self.hairlineImageView?.isHidden = false
    }
}

extension UIView {
    fileprivate var hairlineImageView: UIImageView? {
        return hairlineImageView(in: self)
    }

    fileprivate func hairlineImageView(in view: UIView) -> UIImageView? {
        if let imageView = view as? UIImageView, imageView.bounds.height <= 1.0 {
            return imageView
        }

        for subview in view.subviews {
            if let imageView = self.hairlineImageView(in: subview) { return imageView }
        }

        return nil
    }
}

Answer 2

I know this is an old thread, but I found a solution that works really well:

Subclass UINavigationBar. In your UINavigationBar subclass, override didAddSubview with the following code:

- (void)didAddSubview:(UIView *)subview
{
    [super didAddSubview:subview];

    if ([subview isKindOfClass:[UIImageView class]]) {
        [subview setClipsToBounds:YES];
    }
}

Answer 3

To do this, you should set a custom shadow image. But for the shadow image to be shown you also need to set a custom background image, quote from Apple's documentation:

For a custom shadow image to be shown, a custom background image must also be set with the setBackgroundImage(_:for:) method. If the default background image is used, then the default shadow image will be used regardless of the value of this property.

So:

let navigationBar = navigationController!.navigationBar
navigationBar.setBackgroundImage(#imageLiteral(resourceName: "BarBackground"),
                                                        for: .default)
navigationBar.shadowImage = UIImage()

Above is the only "official" way to hide it. Unfortunately, it removes bar's translucency.

I don't want background image, just color

You have those options:

1. Solid color, no translucency:

   navigationBar.barTintColor = UIColor.redColor()
   navigationBar.isTranslucent = false
   navigationBar.setBackgroundImage(UIImage(), for: .default)
   navigationBar.shadowImage = UIImage()
   

2. Create small background image filled with color and use it.

3. Use 'hacky' method described below. It will also keep bar translucent.

How to keep bar translucent?

To keep translucency you need another approach, it looks like a hack but works well. The shadow we're trying to remove is a hairline UIImageView somewhere under UINavigationBar. We can find it and hide/show it when needed.

Instructions below assume you need hairline hidden only in one controller of your UINavigationController hierarchy.

1. Declare instance variable:

   private var shadowImageView: UIImageView?
   

2. Add method which finds this shadow (hairline) UIImageView:

   private func findShadowImage(under view: UIView) -> UIImageView? {
       if view is UIImageView && view.bounds.size.height <= 1 {
           return (view as! UIImageView)
       }
   
       for subview in view.subviews {
           if let imageView = findShadowImage(under: subview) {
               return imageView
           }
       }
       return nil
   }
   

3. Add/edit viewWillAppear/viewWillDisappear methods:

   override func viewWillAppear(_ animated: Bool) {
       super.viewWillAppear(animated)
   
       if shadowImageView == nil {
           shadowImageView = findShadowImage(under: navigationController!.navigationBar)
       }
       shadowImageView?.isHidden = true
   }
   
   override func viewWillDisappear(_ animated: Bool) {
       super.viewWillDisappear(animated)
   
       shadowImageView?.isHidden = false
   }
   

The same method should also work for UISearchBar hairline, and (almost) anything else you need to hide :)

Many thanks to @Leo Natan for the original idea!

Answer 4

The problem with setting a background image is it removes blurring. You can remove it without setting a background image. See my answer here.

Answer 5

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:

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

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

Answer 6

Try this:

[[UINavigationBar appearance] setBackgroundImage: [UIImage new]  
                                   forBarMetrics: UIBarMetricsDefault];

[UINavigationBar appearance].shadowImage = [UIImage new];

Below image has the explanation (iOS7 NavigationBar):

And check this SO question: iOS7 - Change UINavigationBar border color