If you need to make broad changes to UIKit components, the UIAppearance proxy is your friend: you can treat it like an instance of any given UIKit type, except the changes you make there apply to all new instances of that type. Note: it applies to new instances of that, and won’t change any existing instances you have created.
For example, if you want all navigation bars to have a red background color regardless of where they appear in your app, you could put this into the
didFinishLaunching method of your app delegate:
UINavigationBar.appearance().barTintColor = .red
For more precise changes you can use
appearance(whenContainedInInstancesOf:) and specify a container appearance proxy. For example, you might want to make bar button items one color when they appear in navigation bars and another color when they appear in toolbars:
UIBarButtonItem.appearance(whenContainedInInstancesOf: [UINavigationBar.self]).tintColor = .green UIBarButtonItem.appearance(whenContainedInInstancesOf: [UIToolbar.self]).tintColor = .red
While that’s easy to do, I hope you at least choose better colors!
Available from iOS 5.0
Did this solution work for you? Please pass it on!
Other people are reading…
About the Swift Knowledge Base
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
Become a Swift expert
I wrote a book called Pro Swift that's dedicated to helping you master the Swift language, and it includes seven hours of video demonstrating each technique!