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 ba

Answer 1

In iOS8, if you set the UINavigationBar.barStyle to .Black you can set the bar's background as plain color without the border.

In Swift:

UINavigationBar.appearance().translucent = false
UINavigationBar.appearance().barStyle = UIBarStyle.Black
UINavigationBar.appearance().barTintColor = UIColor.redColor()

Answer 2

As of iOS 13 there is a system API to set or remove the shadow

UIKit uses shadowImage and the shadowColor property to determine the shadow's appearance. When shadowImage is nil, the bar displays a default shadow tinted according to the value in the shadowColor property. If shadowColor is nil or contains the clearColor color, the bar displays no shadow.

    let appearance = UINavigationBarAppearance()
    appearance.shadowImage = nil
    appearance.shadowColor = nil
    navigationController.navigationBar.standardAppearance = appearance

https://developer.apple.com/documentation/uikit/uibarappearance/3198009-shadowimage

Answer 3

Swift 4 //for hiding navigation bar shadow line

navigationController?.navigationBar.shadowImage = UIImage()

Answer 4

For iOS 13:

Use the .shadowColor property

If this property is nil or contains the clear color, the bar displays no shadow

For instance:

let navigationBar = navigationController?.navigationBar
let navigationBarAppearence = UINavigationBarAppearance()
navigationBarAppearence.shadowColor = .clear
navigationBar?.scrollEdgeAppearance = navigationBarAppearence

For iOS 12 and below:

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 5

-(void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];

    UIImage *emptyImage = [UIImage new];
    self.navigationController.navigationBar.shadowImage = emptyImage;
    [self.navigationController.navigationBar setBackgroundImage:emptyImage forBarMetrics:UIBarMetricsDefault];
}

Answer 6

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