Explore the various UI frameworks available for building app interfaces. Discuss the use cases for different frameworks, share best practices, and get help with specific framework-related questions.

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A Summary of the WWDC25 Group Lab - UI Frameworks
At WWDC25 we launched a new type of Lab event for the developer community - Group Labs. A Group Lab is a panel Q&A designed for a large audience of developers. Group Labs are a unique opportunity for the community to submit questions directly to a panel of Apple engineers and designers. Here are the highlights from the WWDC25 Group Lab for UI Frameworks. How would you recommend developers start adopting the new design? Start by focusing on the foundational structural elements of your application, working from the "top down" or "bottom up" based on your application's hierarchy. These structural changes, like edge-to-edge content and updated navigation and controls, often require corresponding code modifications. As a first step, recompile your application with the new SDK to see what updates are automatically applied, especially if you've been using standard controls. Then, carefully analyze where the new design elements can be applied to your UI, paying particular attention to custom controls or UI that could benefit from a refresh. Address the large structural items first then focus on smaller details is recommended. Will we need to migrate our UI code to Swift and SwiftUI to adopt the new design? No, you will not need to migrate your UI code to Swift and SwiftUI to adopt the new design. The UI frameworks fully support the new design, allowing you to migrate your app with as little effort as possible, especially if you've been using standard controls. The goal is to make it easy to adopt the new design, regardless of your current UI framework, to achieve a cohesive look across the operating system. What was the reason for choosing Liquid Glass over frosted glass, as used in visionOS? The choice of Liquid Glass was driven by the desire to bring content to life. The see-through nature of Liquid Glass enhances this effect. The appearance of Liquid Glass adapts based on its size; larger glass elements look more frosted, which aligns with the design of visionOS, where everything feels larger and benefits from the frosted look. What are best practices for apps that use customized navigation bars? The new design emphasizes behavior and transitions as much as static appearance. Consider whether you truly need a custom navigation bar, or if the system-provided controls can meet your needs. Explore new APIs for subtitles and custom views in navigation bars, designed to support common use cases. If you still require a custom solution, ensure you're respecting safe areas using APIs like SwiftUI's safeAreaInset. When working with Liquid Glass, group related buttons in shared containers to maintain design consistency. Finally, mark glass containers as interactive. For branding, instead of coloring the navigation bar directly, consider incorporating branding colors into the content area behind the Liquid Glass controls. This creates a dynamic effect where the color is visible through the glass and moves with the content as the user scrolls. I want to know why new UI Framework APIs aren’t backward compatible, specifically in SwiftUI? It leads to code with lots of if-else statements. Existing APIs have been updated to work with the new design where possible, ensuring that apps using those APIs will adopt the new design and function on both older and newer operating systems. However, new APIs often depend on deep integration across the framework and graphics stack, making backward compatibility impractical. When using these new APIs, it's important to consider how they fit within the context of the latest OS. The use of if-else statements allows you to maintain compatibility with older systems while taking full advantage of the new APIs and design features on newer systems. If you are using new APIs, it likely means you are implementing something very specific to the new design language. Using conditional code allows you to intentionally create different code paths for the new design versus older operating systems. Prefer to use if #available where appropriate to intentionally adopt new design elements. Are there any Liquid Glass materials in iOS or macOS that are only available as part of dedicated components? Or are all those materials available through new UIKit and AppKit views? Yes, some variations of the Liquid Glass material are exclusively available through dedicated components like sliders, segmented controls, and tab bars. However, the "regular" and "clear" glass materials should satisfy most application requirements. If you encounter situations where these options are insufficient, please file feedback. If I were to create an app today, how should I design it to make it future proof using Liquid Glass? The best approach to future-proof your app is to utilize standard system controls and design your UI to align with the standard system look and feel. Using the framework-provided declarative API generally leads to easier adoption of future design changes, as you're expressing intent rather than specifying pixel-perfect visuals. Pay close attention to the design sessions offered this year, which cover the design motivation behind the Liquid Glass material and best practices for its use. Is it possible to implement your own sidebar on macOS without NSSplitViewController, but still provide the Liquid Glass appearance? While technically possible to create a custom sidebar that approximates the Liquid Glass appearance without using NSSplitViewController, it is not recommended. The system implementation of the sidebar involves significant unseen complexity, including interlayering with scroll edge effects and fullscreen behaviors. NSSplitViewController provides the necessary level of abstraction for the framework to handle these details correctly. Regarding the SceneDelagate and scene based life-cycle, I would like to confirm that AppDelegate is not going away. Also if the above is a correct understanding, is there any advice as to what should, and should not, be moved to the SceneDelegate? UIApplicationDelegate is not going away and still serves a purpose for application-level interactions with the system and managing scenes at a higher level. Move code related to your app's scene or UI into the UISceneDelegate. Remember that adopting scenes doesn't necessarily mean supporting multiple scenes; an app can be scene-based but still support only one scene. Refer to the tech note Migrating to the UIKit scene-based life cycle and the Make your UIKit app more flexible WWDC25 session for more information.
Topic: UI Frameworks SubTopic: General
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Jun ’25
Live Q&A Summary - SwiftUI foundations: Build great apps with SwiftUI
Here’s a recap of the Live Q&A for SwiftUI foundations: Build great apps with SwiftUI. If you participated and asked questions, thank you for coming and participating! If you weren’t able to join us live we hope this recap is useful Where can I watch the VOD? Is the sample code “Wishlist” that was shown available for download? You can view the replay of the entire event here https://www.youtube.com/watch?v=Z3vloOtZLkQ The sample code for the Wishlist app will be made available in the coming weeks on the Apple Developer website, we'll send an update via email when it is available. What are the best practices when it comes to building complex navigations in SwiftUI? The developer website has documentation on navigation style best practices. Explore navigation basics like NavigationStack and TabView to get a ground-up understanding. For documentation on navigation APIs see Navigation. How can I integrate UIKit with my SwiftUI app? What about adding SwiftUI into my UIKit app? See UIKit integration: Add UIKit views to your SwiftUI app, or use SwiftUI views in your UIKit app. Both UIKit and SwiftUI provide API to show a view hierarchy of the other. For UIKit to SwiftUI, you would use UIViewControllerRepresentable. For SwiftUI to UIKit, you would use UIHostingController. Landmarks: Interfacing with UIKit walks you through step by step how to implement UIKit in SwiftUI with UIViewControllerRepresentable, and this WWDC22 video demonstrates UIHostingController, for those that want to add SwiftUI to their UIKit. Does Wishlist feature a new iOS 26 font? How can I add custom fonts and text of my app? We’re glad to hear many of you liked wide text shown in Wishlist, however, It is the default system font with some light SwiftUI styling! Check it out for yourself in the sample code when made available, and you can learn more about customizing fonts and text by seeing Font and Applying custom fonts to text. Does Xcode have a dependency graph we can use to optimize our SwiftUI Views? Xcode comes with Instruments. Instruments is the best way to figure out what is causing excessive updates and other issues with performance. That link provides direct tutorials and resources for how to use and understand. Previews also have many useful tools for analyzing SwiftUI views, for more info see Previews in Xcode Check out this video from our latest WWDC Optimize SwiftUI performance with Instruments for information on how to use Instruments to profile and optimize your app with real-world applications If you still have questions, Check out the Instruments section of these forums and create a post so the community has the opportunity to help guide you. Are there UI debugging tools to help diagnose layout issues? Yes, Xcode also features a View Debugger located by selecting the View Debug Hierarchy, pictured below. Use the View Debugger to capture and inspect your view hierarchy, identifying which views affect window sizing. The SwiftUI Inspector also lets you examine view frames and layout behavior. See Diagnosing issues in the appearance of a running app to learn about debugging visual and layout issues. As an absolute beginner, what would be the first go-to step to go for training? Do I need prior knowledge of frameworks to get started with SwiftUI? A great place to learn how to develop for Apple platforms is with Pathways! Many developers start with Develop in Swift tutorials, which exposes you to several frameworks while teaching you the basics of SwiftUI. When you're ready to take your learning further, you can read the documentation for the specific frameworks that interest you at https://developer.apple.com/documentation/.
Topic: UI Frameworks SubTopic: SwiftUI
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iOS17 UITextView inputView becomFirstResponder does not work
Simplely, when we set UITextView.inputView and then call becomeFirstResponder, but the custom inputView could not show expectedly just like before. We test this code in iOS17 and below, while only iOS17 does not work. And xcode console print these logs: Failed to retrieve snapshot. -[RTIInputSystemClient remoteTextInputSessionWithID:performInputOperation:] perform input operation requires a valid sessionID -[RTIInputSystemClient remoteTextInputSessionWithID:performInputOperation:] perform input operation requires a valid sessionID -[RTIInputSystemClient remoteTextInputSessionWithID:performInputOperation:] perform input operation requires a valid sessionID -[RTIInputSystemClient remoteTextInputSessionWithID:performInputOperation:] perform input operation requires a valid sessionID Unsupported action selector setShiftStatesNeededInDestination:autoShifted:shiftLocked: Unsupported action selector setShiftStatesNeededInDestination:autoShifted:shiftLocked: Unsupported action selector setShiftStatesNeededInDestination:autoShifted:shiftLocked: Unsupported action selector setShiftStatesNeededInDestination:autoShifted:shiftLocked:
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Apr ’25
Xcode 14: [Assert] UINavigationBar decoded as unlocked for UINavigationController
In Xcode 14 RC, I'm seeing this in the Console: [Assert] UINavigationBar decoded as unlocked for UINavigationController, or navigationBar delegate set up incorrectly. Inconsistent configuration may cause problems. navigationController=<MasterNavigationController: 0x135016200>, navigationBar=<UINavigationBar: 0x134f0aec0; frame = (0 20; 0 50); opaque = NO; autoresize = W; layer = <CALayer: 0x600000380be0>> delegate=0x135016200 The above message displays exactly four times immediately at app launch (top of the console) then does not repeat. MasterNavigationController is the internal class for the app's navigation controller. It is in a Storyboard, with very minimal ObjC code. I am not setting any specific size for the nav bar. I don't remember seeing this in earlier builds of Xcode, but I can't swear to it that this is new. No assertion actually fires.
Topic: UI Frameworks SubTopic: UIKit Tags:
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Mar ’25
iOS 16.0 beta 7 broke Text(Date(), style: .timer) in SwiftUI widgets
Hi, In my apps, the recent iOS 16.0 beta 7 (20A5356a) broke the .timer DateStyle property of the Text view, in a SwiftUI widget. In previous OS and beta, Text(Date(), style: .timer) was correctly displaying an increasing counter. In iOS 6.0 beta 7, Text(Date(), style: .timer) does not update anymore, (and is offset to the left). The other DateStyle (like .offset, .relative, ...) seems to update correctly. Anyone noticed that (very specific) problem ?
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Jul ’25
Checking the contents of a TextField variable method not working
Hoping someone can help me with this… The error is… Generic parameter ‘/‘ cannot be inferred. .multilineTextAlignment(.center) .onAppear(perform: { var checkFirstCardLatitude = cards.firstCardLatitude let charArray = Array(checkFirstCardLatitude) let allowed: [Character] = ["-", ".", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"] for char in charArray { if char != allowed { cards.firstCardLatitude = "000.000000" // Reset Text Field } } })
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May ’25
SwiftUI - Placing ToolbarItem on .keyboard does not work
I have a regular SwiftUI View embedded inside of a NavigationStack. In this view, I make use of the .searchable() view modifier to make that view searchable. I have a button on the toolbar placed on the .confirmationAction section, which is a problem when a User types into the search bar and the button gets replaced by the SearchBar's cancel button. Thus, I conditionally place the button, depending on whether a User is searching, either on the navigationBar or on the keyboard. The latter does not work however, as the button does not show and when trying to debug the View Hierarchy, Xcode throws an error saying the View Hierarchy could not be displayed. If I set the button to be on the .bottomBar instead, it shows up perfectly and the View Hierarchy also displays with no further issue. Has someone come across this issue and if so, how did you get it fixed? Thank you in advance.
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Jul ’25
[macOS Sequoia] Using RegisterEventHotkey with option and shift modifiers doesn't working anymore
Hello. In my app, I use RegisterEventHotkey to implement global keyboard shortcuts to trigger actions. Up until macOS Sequoia, I was able to use a keyboard shortcut with option and shift as the modifiers, like option shift 2 (⌥ ⇧ 2). Now, on macOS Sequoia, using RegisterEventHotkey to register a hotkey with those exact modifiers (option and shift), regardless of the key, fails with the error -9868 (eventInternalErr). Is this a documented and wanted change, or is this a bug? Other modifier keys (just command, command option, command shift, command control, control shift, etc), all work. Any insight into this would be appreciated. (Feedback filed: FB15163561) Thank you, Matthias
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Nov ’25
Swift UI on iOS 14 not assigning new object to @State property
On iOS 13 I used to use optional @State properties to adapt views. In my case, the presented view would either create a new object (an assignment) if the state that is passed into it is nil, or edit the assignment if an assignment was passed in. This would be done in the action block of a Button and it worked beautifully. On iOS 14 / Xcode 12 this no longer seems to work. Given the following code which creates a new assignment and passes it into the editor view when the user taps a "New Assignment" button, the value of assignment remains nil. Is anyone else experiencing similar behaviour? struct ContentView: View { &#9;&#9;@Environment(\.managedObjectContext) var context &#9;&#9;@State var assignmentEditorIsPresented = false &#9;&#9;@State var assignment: Assignment? = nil &#9;&#9;var Body: some View { &#9;&#9;&#9;&#9;[...] &#9;&#9;&#9;&#9;Button("New Assignment", action: { &#9;&#9;&#9;&#9;&#9;&#9;self.assignment = Assignment(context: context) &#9;&#9;&#9;&#9;&#9;&#9;self.assignmentEditorIsPresented = true &#9;&#9;&#9;&#9;}) &#9;&#9;&#9;&#9;.sheet(isPresented: assignmentEditorIsPresented) { &#9;&#9;&#9;&#9;&#9;&#9;[...] &#9;&#9;&#9;&#9;} &#9;&#9;} } What's even weirder is that I tried adding a random piece of state, an Int, to this view and modifying it right before the assignment state (between lines 9 and 10) and it didn't change either.
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Mar ’25
Invalid Numeric Value (NaN) Error in SwiftUI's TextField on Long-Press
I'm experiencing a peculiar issue with SwiftUI's TextField. Whenever I long-press on the TextField, the console outputs an error about passing an invalid numeric value (NaN, or not-a-number) to the CoreGraphics API. This issue persists even in a new Xcode project with minimal code. Code Snippet: import SwiftUI struct ContentView: View { @State private var text: String = "" var body: some View { TextField("Placeholder", text: $text) } } Error: this application, or a library it uses, has passed an invalid numeric value (NaN, or not-a-number) to CoreGraphics API and this value is being ignored. Please fix this problem. Steps to Reproduce: Create a new SwiftUI project in Xcode. Add a TextField to the ContentView. Run the app on a device or simulator. Long-press inside the TextField. What I've Tried: Updating to the latest version of Xcode and iOS. Using UIViewRepresentable to wrap a UIKit UITextField. Creating a new Xcode project to isolate the issue. None of these steps have resolved the issue. Questions: Has anyone else encountered this problem? Are there any known workarounds for this issue? Is this a known bug, and if so, has it been addressed in any updates?
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Mar ’25
`onTapGesture` not triggered on `Map` views
When building with iOS 26 SDK beta 5 (23A5308f), onTapGesture is no longer being triggered on Map views. This appears to be a regression in beta 5 specifically, as this issue was not present in beta 4. How to reproduce Code The following code demonstrates the issue, as seen in the videos below. import MapKit import SwiftUI struct ContentView: View { @State private var location = CGPoint.zero var body: some View { Map() .onTapGesture { location in self.location = location } .safeAreaInset(edge: .bottom) { VStack(alignment: .center) { Text("iOS \(UIDevice.current.systemVersion)") .font(.largeTitle) Text("Tapped Location") Text("\(location.x), \(location.y)") } .frame(maxWidth: .infinity, alignment: .center) .background(.background) } } } Demo The gifs below show the behavior in iOS 18.5 (in which the tap gestures are recognized and tapped coordinate is displayed in the safe area inset) and iOS 26 beta 5 (in which the tap gestures have no effect): iOS 18 iOS 26 Next steps? Is there a recommended workaround for this issue?
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Sep ’25
UISegmentedControl Not Switching Segments on iOS Beta 26
While testing my application on iOS beta 26, I am experiencing issues with the native UISegmentedControl component from UIKit. After implementing the control, I noticed that I am unable to switch to the second segment option—the selection remains fixed on the first segment regardless of user interaction. I have already reviewed the initial configuration of the control, the addition of the segments, and the implementation of the target-action, but the issue persists. I would like to understand what could be causing this behavior and if there are any specific adjustments or workarounds for iOS 26. I created a minimal application containing only a UISegmentedControl to clearly demonstrate the issue.
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Aug ’25
SwiftUI Gestures prevent scrolling with iOS 18
I added gesture support to my app that supports iOS 16 and 17 and have never had issues with it. However, when I compiled my app with Xcode 16 I immediately noticed a problem with the app when I ran it in the simulator. I couldn't scroll up or down. I figured out it’s because of my gesture support. My gesture support is pretty simple. let myDragGesture = DragGesture() .onChanged { gesture in self.offset = gesture.translation } .onEnded { _ in if self.offset.width > threshold { ...some logic } else if self.offset.width < -threshold { ...some other logic } logitUI.debug("drag gesture width was \(self.offset.width)") self.offset = .zero } If I pass nil to .gesture instead of myDragGesture then scrolling starts working again. Here’s some example output when I’m trying to scroll down. These messages do NOT appear when I run my app on an iOS 16/17 simulator with Xcode 15. drag gesture width was 5.333328 drag gesture width was -15.333344 drag gesture width was -3.000000 drag gesture width was -24.333328 drag gesture width was -30.666656 I opened FB14205678 about this.
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May ’25
Source view disappearing when interrupting a zoom navigation transition
When I use the .zoom transition in a navigation stack, I get a glitch when interrupting the animation by swiping back before it completes. When doing this, the source view disappears. I can still tap it to trigger the navigation again, but its not visible on screen. This seems to be a regression in iOS 26, as it works as expected when testing on iOS 18. Has someone else seen this issue and found a workaround? Is it possible to disable interrupting the transition? Filed a feedback on the issue FB19601591 Screen recording: https://share.icloud.com/photos/04cio3fEcbR6u64PAgxuS2CLQ Example code @State var showDetail = false @Namespace var namespace var body: some View { NavigationStack { ScrollView { showDetailButton } .navigationTitle("Title") .navigationBarTitleDisplayMode(.inline) .navigationDestination(isPresented: $showDetail) { Text("Detail") .navigationTransition(.zoom(sourceID: "zoom", in: namespace)) } } } var showDetailButton: some View { Button { showDetail = true } label: { Text("Show detail") .padding() .background(.green) .matchedTransitionSource(id: "zoom", in: namespace) } } }
Topic: UI Frameworks SubTopic: SwiftUI
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NSDocument doesn't autosave last changes
I had noticed an unsettling behaviour about NSDocument some years ago and created FB7392851, but the feedback didn't go forward, so I just updated it and hopefully here or there someone can explain what's going on. When running a simple document-based app with a text view, what I type before closing the app may be discarded without notice. To reproduce it, you can use the code below, then: Type "asdf" in the text view. Wait until the Xcode console logs "saving". You can trigger it by switching to another app and back again. Type something else in the text view, such as "asdf" on a new line. Quit the app. Relaunch the app. The second line has been discarded. Am I doing something wrong or is this a bug? Is there a workaround? class ViewController: NSViewController { @IBOutlet var textView: NSTextView! } class Document: NSDocument { private(set) var text = "" override class var autosavesInPlace: Bool { return true } override func makeWindowControllers() { let storyboard = NSStoryboard(name: NSStoryboard.Name("Main"), bundle: nil) let windowController = storyboard.instantiateController(withIdentifier: NSStoryboard.SceneIdentifier("Document Window Controller")) as! NSWindowController (windowController.contentViewController as? ViewController)?.textView.string = text self.addWindowController(windowController) } override func data(ofType typeName: String) throws -> Data { Swift.print("saving") text = (windowControllers.first?.contentViewController as? ViewController)?.textView.string ?? "" return Data(text.utf8) } override func read(from data: Data, ofType typeName: String) throws { text = String(decoding: data, as: UTF8.self) (windowControllers.first?.contentViewController as? ViewController)?.textView.string = text } }
Topic: UI Frameworks SubTopic: AppKit Tags:
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Oct ’25
UIKit flip animation bugged in 26.1
Hello. I have an 12 year old app that still has some objective-c code in it. I have a place where i have a flip animation between 2 view controllers that looks like this: [UIView transitionFromView:origView toView:newViewController.view duration:0.5 options:UIViewAnimationOptionTransitionFlipFromRight completion:nil]; It has looked like this since 2012 at least. In our production release, it works prior to 26.1, but in 26.1 and 26.2, the flip is off-center and looks weird. it's like both edges flip the same way. It's a little bit hard to explain. If seen at least 2 other app store apps that i have installed behave this way too, from 26.1 and onwards. Anyone else seen this? Is there anything that can be done about it? Thankful for thoughts.
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Since iOS 18.3, icons are no longer generated correctly with QLThumbnailGenerator
Since iOS 18.3, icons are no longer generated correctly with QLThumbnailGenerator. No error is returned either. But this error message now appears in the console: Error returned from iconservicesagent image request: <ISTypeIcon: 0x3010f91a0>,Type: com.adobe.pdf - <ISImageDescriptor: 0x302f188c0> - (36.00, 36.00)@3x v:1 l:5 a:0:0:0:0 t:() b:0 s:2 ps:0 digest: B19540FD-0449-3E89-AC50-38F92F9760FE error: Error Domain=NSOSStatusErrorDomain Code=-609 "Client is disallowed from making such an icon request" UserInfo={NSLocalizedDescription=Client is disallowed from making such an icon request} Does anyone know this error? Is there a workaround? Are there new permissions to consider? Here is the code how icons are generated: let request = QLThumbnailGenerator.Request(fileAt: url, size: size, scale: scale, representationTypes: self.thumbnailType) request.iconMode = true let generator = QLThumbnailGenerator.shared generator.generateRepresentations(for: request) { [weak self] thumbnail, _, error in }
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Nov ’25