Remove that shadow!

UIKit can be so frustrating sometimes. I was trying to remove a shadow from UINavigationBar, and it turns out there is a property for doing this…

navigationBar.shadow = <something>

Perfect! or not… Apparently, it only works if you have a custom image as your bar background

The default value is nil, which corresponds to the default shadow image. When non-nil, this property represents a custom shadow image to show instead of the default. For a custom shadow image to be shown, a custom background image must also be set with the setBackgroundImage:forBarMetrics: method. If the default background image is used, then the default shadow image will be used regardless of the value of this property.

So, I cannot use a solid colored background without a shadow… after looking around online, I found bunch of extensions on UIImage that returns an image of a given size and color, but I felt that custom drawing was a little overkill here. My solution is as follows:

extension UINavigationBar {
    
    func removeShadow() {
        if let view = removeShadowFromView(self) {
            view.hidden = true
        }
    }
    
    func removeShadowFromView(view: UIView) -> UIImageView? {
        if (view.isKindOfClass(UIImageView) && view.bounds.size.height <= 1) {
            return view as? UIImageView
        }
        for subView in view.subviews {
            if let imageView = removeShadowFromView(subView as UIView) {
                return imageView
            }
        }
        return nil
    }   
}

This way, I simply call

navigationController?.navigationBar.removeShadow()

and all is right with the world. Feel free to use this extension in your own work, it’s nothing particularly genius, but it sure helps me out. This is based on some Objective-C code I found here

Update for iOS 10: I changed the above code so it “hides” the shadow, rather than removing it. This is confirmed working on both iOS 9 and 10. The removeFromSuperview() method doesn’t work on iOS 10.