SwiftUI is Apple's declarative Swift API for defining graphical user interfaces. Use this tag for questions about SwiftUI on any platform. Be sure to include the [Swift] tag as well.
SwiftUI is a closed-source Apple framework providing a declarative Swift-only API for defining the appearance and behavior of graphical user interfaces. Apple's reference documentation describes SwiftUI as follows:
SwiftUI provides views, controls, and layout structures for declaring your app's user interface. The framework provides event handlers for delivering taps, gestures, and other types of input to your app, and tools to manage the flow of data from your app's models down to the views and controls that users will see and interact with.
Though apps can now be built fully with SwiftUI, using the SwiftUI lifecycle, one can also embed the top-level SwiftUI View in an appropriate hosting adapter for the platform (NSHostView, NSHostingController, UIHostingController, or WKHostingController) for apps with non-SwiftUI lifecycles.
SwiftUI integrates with Apple's older imperative AppKit, UIKit, and WatchKit frameworks. An NSView or UIView can embed a SwiftUI View and vice versa.
SwiftUI supports live previews and dynamic replacement (hot swapping) in Xcode 11 on macOS 10.15 (Catalina) and later, and on devices running an operating system that supports SwiftUI (see the list below).
Apple first revealed SwiftUI at WWDC on June 3, 2019 and made it available in the first beta release of Xcode 11.
SwiftUI is part of the following SDKs:
- macOS 10.15 (Catalina) and later,
- iOS 13 and later,
- tvOS 13 and later,
- watchOS 6 and later.
SwiftUI apps cannot be deployed to older platforms.
In addition to the official documentation, Apple offers two tutorials (Introducing SwiftUI and the first part of Develop Apps for iOS) entirely devoted to SwiftUI, as well as sample code (Fruta: Building a Feature-Rich App with SwiftUI).
