NEW: My new book Pro SwiftUI is out now – level up your SwiftUI skills today! >>

What is the UIAppearance proxy?

Swift version: 5.6

Paul Hudson    @twostraws   

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!

Hacking with Swift is sponsored by Play

SPONSORED Play is the first native iOS design tool created for designers and engineers. You can install Play for iOS and iPad today and sign up to check out the Beta of our macOS app with SwiftUI code export. We're also hiring engineers!

Click to learn more about Play!

Sponsor Hacking with Swift and reach the world's largest Swift community!

Available from iOS 5.0

Similar solutions…

About the Swift Knowledge Base

This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.

BUY OUR BOOKS
Buy Pro Swift Buy Pro SwiftUI Buy Swift Design Patterns Buy Testing Swift Buy Hacking with iOS Buy Swift Coding Challenges Buy Swift on Sundays Volume One Buy Server-Side Swift Buy Advanced iOS Volume One Buy Advanced iOS Volume Two Buy Advanced iOS Volume Three Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with macOS Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Beyond Code

Was this page useful? Let us know!

Average rating: 4.5/5

 
Unknown user

You are not logged in

Log in or create account
 

Link copied to your pasteboard.