App design and UI
Choose a programming approach to build your app, create your app’s interface, and implement the fundamental behaviors that your app requires.
Overview
At the start of every new project, you need to choose an app-builder technology to use for your initial code. App-builder technologies define the programming approach you take for your app’s interface, event-handling code, and other behaviors. You can choose one of these programming approaches for your app, or combine the approaches.
Each platform defines the overall look for views and controls, and your app-builder technology determines how you create and manage your interface. Build your interface with standard views and controls, a mixture of standard and custom views, or entirely custom content.
SwiftUI is the best option when you’re learning to program for Apple platforms, or when you want to create a new app. With SwiftUI, you build your app’s interface and content using a declarative programming model. With this model, you describe the behaviors and appearance you want, and SwiftUI creates and manages the interface for you. Changes are data driven, so when you update variables that affect the state of a view, SwiftUI refreshes your interface for you.
Use SwiftUI to build apps for iOS, iPadOS, macOS, tvOS, visionOS, and watchOS and the Swift programming language.
UIKit and AppKit offer a more traditional, object-oriented approach to building apps. These frameworks provide a library of objects that you assemble and customize to achieve the behavior you want. For example, you assemble your interface from standard and custom views and place the logic for managing view interactions in custom controller objects. Each object manages its own behavior, and your custom code defines the overall behavior of your app.
Use UIKit to build apps for iOS, iPadOS, tvOS, visionOS, and Mac Catalyst. Use AppKit to build apps for macOS. Build your app using either Swift or the Objective-C programming language.
No matter which app-builder technology you choose, most of the components you use to build your interface are the same. Before you build your interface, learn about the different components available to you, and learn how different platforms use those components. You can also learn about other technologies that impact the design of your interface and how you display content.
Interfaces across Apple platforms feature a new dynamic material called Liquid Glass, which combines the optical properties of glass with a sense of fluidity. Learn how to leverage Liquid Glass to make sure your interface looks right at home on Apple platforms.