This topic area is about the programming languages themselves, not about any specific API or tool. If you have an API question, go to the top level and look for a subtopic for that API. If you have a question about Apple developer tools, start in the Developer Tools & Services topic. For Swift questions: If your question is about the SwiftUI framework, start in UI Frameworks > SwiftUI. If your question is specific to the Swift Playground app, ask over in Developer Tools & Services > Swift Playground If you’re interested in the Swift open source effort — that includes the evolution of the language, the open source tools and libraries, and Swift on non-Apple platforms — check out Swift Forums If your question is about the Swift language, that’s on topic for Programming Languages > Swift, but you might have more luck asking it in Swift Forums > Using Swift. General: Forums topic: Programming Languages Swift: Forums subtopic: Programming Languages > Swift Forums tags: Swift Developer > Swift website Swift Programming Language website The Swift Programming Language documentation Swift Forums website, and specifically Swift Forums > Using Swift Swift Package Index website Concurrency Resources, which covers Swift concurrency How to think properly about binding memory Swift Forums thread Other: Forums subtopic: Programming Languages > Generic Forums tags: Objective-C Programming with Objective-C archived documentation Objective-C Runtime documentation Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com"

When using UITraitBridgedEnvironmentKey to pass a trait value to the swift environment, it causes a crash when trying to access the value from the environment. The issue seems to be related to how swift uses the UITraitBridgedEnvironmentKey protocol since the crash occurs in swift::_getWitnessTable () from lazy protocol witness table accessor…. It can occur when calling any function that is generic using the UITraitBridgedEnvironmentKey type. I originally encountered the issue when trying to use a UITraitBridgedEnvironmentKey in SwiftUI, but have been able to reproduce the issue with any function with a similar signature. https://developer.apple.com/documentation/swiftui/environmentvalues/subscript(_:)-9zku Steps to Reproduce Requirements for the issue to occur Project with a minimum iOS version of iOS 16 Build the project with Xcode 26 Run on iOS 18 Add the following code to a project and call foo(key: MyCustomTraitKey.self) from anywhere. @available(iOS 17.0, *) func foo<K>(key: K.Type) where K: UITraitBridgedEnvironmentKey { // Crashes before this is called } @available(iOS 17.0, *) public enum MyCustomTraitKey: UITraitBridgedEnvironmentKey { public static let defaultValue: Bool = false public static func read(from traitCollection: UITraitCollection) -> Bool { false } public static func write(to mutableTraits: inout UIMutableTraits, value: Bool) {} } // The crash will occur when calling this. It can be added to a project anywhere // The sample project calls it from scene(_:willConnectTo:options:) foo(key: MyCustomTraitKey.self) For example, I added it to the SceneDelegate in a UIKit Project class SceneDelegate: UIResponder, UIWindowSceneDelegate { var window: UIWindow? func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) { if #available(iOS 17, *) { // The following line of code can be placed anywhere in a project, `SceneDelegate` is just a convenient place to put it to reproduce the issue. foo(key: MyCustomTraitKey.self) // ^ CRASH: Thread 1: EXC_BAD_ACCESS (code=1, address=0x10) } } } Actual Behaviour The app crashes with the stack trace showing the place calling foo but before foo is actually called. (ie, a breakpoint or print in foo is never hit) #0 0x000000019595fbc4 in swift::_getWitnessTable () #1 0x0000000104954128 in lazy protocol witness table accessor for type MyCustomTraitKey and conformance MyCustomTraitKey () #2 0x0000000104953bc4 in SceneDelegate.scene(_:willConnectTo:options:) at .../SceneDelegate.swift:20 The app does not crash when run on iOS 17, or 26 or when the minimum ios version is raised to iOS 17 or higher. It also doesn't crash on iOS 16 since it's not calling foo since UITraitBridgedEnvironmentKey was added in iOS 17. Expected behaviour The app should not crash. It should call foo on iOS 17, 18, and 26.

Hi, we are developing a screen time management app. The app locks the device after it was used for specified amount of time. After updating to iOS 26.2, we noticed a huge issue: the events started to fire (reach the threshold) in the DeviceActivityMonitorExtension prematurely, almost immediately after scheduling. The only solution we've found is to delete the app and reboot the device, but the effect is not lasting long and this does not always help. Before updating to iOS 26, events also used to sometimes fire prematurely, but rescheduling the event often helped. Now the rescheduling happens almost every second and the events keep reaching the threshold prematurely. Can you suggest any workarounds for this issue?

Hello, After upgrading to macOS 26.2, I’ve noticed a significant performance regression when calling evaluateJavaScript in an iOS App running on Mac (WKWebView, Swift project). Observed behavior On macOS 26.2, the callback of evaluateJavaScript takes around 3 seconds to return. This happens not only for: evaluateJavaScript("navigator.userAgent") but also for simple or even empty scripts, for example: evaluateJavaScript("") On previous macOS versions, the same calls typically returned in ~200 ms. Additional testing I created a new, empty Objective-C project with a WKWebView and tested the same evaluateJavaScript calls. In the Objective-C project, the callback still returns in ~200 ms, even on macOS 26.2. Question Is this a known issue or regression related to: iOS Apps on Mac, Swift + WKWebView, or behavioral changes in evaluateJavaScript on macOS 26.2? Any information about known issues, internal changes, or recommended workarounds would be greatly appreciated. Thank you. Test Code Swift class ViewController: UIViewController { private var tmpWebView: WKWebView? override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view. setupUserAgent() } func setupUserAgent() { let t1 = CACurrentMediaTime() tmpWebView = WKWebView(frame: .zero) tmpWebView?.isInspectable = true tmpWebView?.evaluateJavaScript("navigator.userAgent") { [weak self] result, error in let t2 = CACurrentMediaTime() print("[getUserAgent] \(t2 - t1)s") self?.tmpWebView = nil } } } Test Code Objective-C - (void)scene:(UIScene *)scene willConnectToSession:(UISceneSession *)session options:(UISceneConnectionOptions *)connectionOptions { NSTimeInterval startTime = [[NSDate date] timeIntervalSince1970]; WKWebView *webView = [[WKWebView alloc] init]; dispatch_async(dispatch_get_main_queue(), ^{ [webView evaluateJavaScript:@"navigator.userAgent" completionHandler:^(id result, NSError *error) { NSTimeInterval endTime = [[NSDate date] timeIntervalSince1970]; NSLog(@"[getUserAgent]: %.2f s", (endTime - startTime)); }]; }); }

Description I've encountered a consistent hang/freeze issue in SwiftUI applications when using nested LazyVStack containers with Accessibility Inspector (simulator) or VoiceOver (physical device) enabled. The application becomes completely unresponsive and must be force-quit. Importantly, this hang occurs in a minimal SwiftUI project with no third-party dependencies, suggesting this is a framework-level issue with the interaction between SwiftUI's lazy view lifecycle and the accessibility system. Reproduction Steps I've created a minimal reproduction project available here: https://github.com/pendo-io/SwiftUI_Hang_Reproduction To Reproduce: Create a SwiftUI view with the following nested LazyVStack structure: struct NestedLazyVStackView: View { @State private var outerSections: [Int] = [] @State private var innerRows: [Int: [Int]] = [:] var body: some View { ScrollView { LazyVStack(alignment: .leading, spacing: 24) { ForEach(outerSections, id: \.self) { section in VStack(alignment: .leading, spacing: 8) { Text("Section #\(section)") // Nested LazyVStack LazyVStack(alignment: .leading, spacing: 2) { ForEach(innerRows[section] ?? [], id: \.self) { row in Text("Section #\(section) - Row #\(row)") .onAppear { // Load more data when row appears loadMoreInner(section: section) } } } } .onAppear { // Load more sections when section appears loadMoreOuter() } } } } } } Enable Accessibility Inspector in iOS Simulator: Xcode → Open Developer Tool → Accessibility Inspector Select your running simulator Enable Inspection mode (eye icon) Navigate to the view and start scrolling Result: The application hangs and becomes unresponsive within a few seconds of scrolling Expected Behavior The application should remain responsive when Accessibility Inspector or VoiceOver is enabled, allowing users to scroll through nested lazy containers without freezing. Actual Behavior The application freezes/hangs completely CPU usage may spike The app must be force-quit to recover The hang occurs consistently and is reproducible Workaround 1: Replace inner LazyVStack with VStack LazyVStack { ForEach(...) { section in VStack { // ← Changed from LazyVStack ForEach(...) { row in ... } } } } Workaround 2: Embed in TabView TabView { NavigationStack { NestedLazyVStackView() // ← Same nested structure, but no hang } .tabItem { ... } } Interestingly, wrapping the entire navigation stack in a TabView prevents the hang entirely, even with the nested LazyVStack structure intact. Questions for Apple Is there a known issue with nested LazyVStack containers and accessibility traversal? Why does wrapping the view in a TabView prevent the hang? Are there recommended patterns for using nested lazy containers with accessibility support? Is this a timing issue, a deadlock, or an infinite loop in the accessibility system? Why that happens? Reproduction Project A complete, minimal reproduction project is available at: https://github.com/pendo-io/SwiftUI_Hang_Reproduction

I have the following code that renders a one-page PDF: func render() -> URL { let renderer = ImageRenderer(content: pdfView()) let url = URL.documentsDirectory.appending(path: "filename.pdf") renderer.render { size, context in var document = CGRect(x: 0, y: 0, width: 2550, height: 3300) guard let pdf = CGContext(url as CFURL, mediaBox: &document, nil) else { return } pdf.beginPDFPage(nil) context(pdf) pdf.endPDFPage() pdf.closePDF() } return url } func pdfView() -> some View { Text("View") } How can this be modified so that it renders a PDF with more than one page?

I tried making a concurrency-safe data queue. It was going well, until memory check tests crashed. It's part of an unadvertised git project. Its location is: https://github.com/CTMacUser/SynchronizedQueue/commit/84a476e8f719506cbd4cc6ef513313e4e489cae3 It's the blocked-off method "`memorySafetyReferenceTypes'" in "SynchronizedQueueTests.swift." Note that the file and its tests were originally AI slop.

In WKWebView, there is the WKUIDelegate method: func webView(_ webView: WKWebView, createWebViewWith configuration: WKWebViewConfiguration, for navigationAction: WKNavigationAction, windowFeatures: WKWindowFeatures) -> WKWebView? {} This delegate method provides a callback when a new window (for example, target="_blank") is requested in the web view. However, in native SwiftUI (iOS 26), WebView / WebPage APIs do not provide an equivalent delegate method to handle new window requests. As a workaround, I am using the following method: public func decidePolicy(for action: WebPage.NavigationAction, preferences: inout WebPage.NavigationPreferences) async -> WKNavigationActionPolicy {} In this method, when action.target == nil, I treat it as a new window request. My question: Is relying on action.target == nil in decidePolicy a reliable and future-safe way to detect new window requests in SwiftUI’s WebView, or is there a better or more recommended approach for handling target="_blank" / new window navigation in the SwiftUI WebView APIs? Code: public func decidePolicy(for action: WebPage.NavigationAction, preferences: inout WebPage.NavigationPreferences) async -> WKNavigationActionPolicy { guard let webPage = webPage else { return .cancel } // Handle case where target frame is nil (e.g., target="_blank" or window.open) // This indicates a new window request if action.target == nil { print("Target frame is nil - new window requested") // WORKAROUND: Until iOS 26 WebPage UI protocol is available, we handle new windows here // Try to create a new WebPage through UI plugins if handleCreateWebPage(for: webPage, navigationAction: action) != nil { // Note: The new WebPage has been created and published to the view return .allow } } return .allow }

I have an NSWindowController with several IBOutlets created in storyboard. I want to add an NSView and fill it with some color. I need to place it at a specific position in views hierarchy. I have tried 2 ways, no one succeeds. First. include a custom view in storyboard connect to an IBOutlet in an init of controller, set the layer for the view Result: crash Second build programmatically Result: I do not find where to put this code in the controller code That's basic Cocoa, but way more painful than iOS.

Overview In iOS 26, a List embedded in a NavigationStack inside a TabView exhibits a visual glitch when switching tabs. When the list is scrolled such that some rows are partially obscured by the navigation bar, the system correctly applies a fade/opacity effect to those rows. However, if the user switches to another tab while rows are in this partially obscured (faded) state, those rows briefly flash at full opacity during the tab transition before disappearing. This flash is visually distracting and appears to be inconsistent with the intended scroll-edge opacity behavior. The issue occurs only for rows partially obscured by the navigation bar. Rows partially obscured by the tab bar do not exhibit this flashing behavior. Steps to Reproduce: Run the attached minimal reproduction on iOS 26. Open the first tab. Scroll the list so that some rows are partially hidden behind the navigation bar (showing the native faded appearance). While rows are in this partially faded state, switch to the second tab. Observe that the faded rows briefly render fully opaque during the tab switch. Expected Behavior: Rows that are partially obscured by the navigation bar should maintain consistent opacity behavior during tab transitions, without flashing to full opacity. import SwiftUI @main struct NavBarReproApp: App { /// Minimal repro for iOS 26: /// - TabView with two tabs /// - First tab: NavigationStack + List /// - Scroll so some rows are partially behind the nav bar (faded) /// - Switch tabs: those partially-faded rows briefly flash fully opaque. Partially faded rows under the tab bar do not flash private let items = Array(0..<200).map { "Row \($0)" } var body: some Scene { WindowGroup { TabView { NavigationStack { List { ForEach(items, id: \.self) { item in Text(item) } } .navigationTitle("One") .navigationBarTitleDisplayMode(.inline) } .tabItem { Label("One", systemImage: "1.circle") } NavigationStack { Text("Second tab") .navigationTitle("Two") .navigationBarTitleDisplayMode(.inline) } .tabItem { Label("Two", systemImage: "2.circle") } } } } }

The crash is specific to iOS 26.2 prior versions working fine. WKScriptMessageHandler delegate func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) Name attribute is accessible but WKScriptMessage body attribute causes crash The object seems to be not accessible(not in memory) self.webkit.configuration.userContentController.add(self, name: "sampleHandler") self.webkit.load(request) func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) { print(message.name) // works print(message.body) // crashes }

I have TabView in ContentView and I want to add TabView for OnboardingView in OtherView, every things work, but it is throw error for TabView in OtherView like "Trailing closure passed to parameter of type 'Int' that does not accept a closure" I do not know why? Any idea? ContentView: struct TabView : View {       var body: some View{           VStack(spacing: 0){ ....... } OtherView:    VStack {     TabView {       ForEach(onboardingData) { onboardingItem in          OnboardingCard(onboardingItem: onboardingItem)       }   }   .tabViewStyle(PageTabViewStyle(indexDisplayMode: .automatic))   .indexViewStyle(PageIndexViewStyle (backgroundDisplayMode:   .always))   .foregroundColor(.white) }

I added a Content Filter to my app, and when running it in Xcode (Debug/Release), I get the expected permission prompt: "Would like to filter network content (Allow / Don't Allow)". However, when I install the app via TestFlight, this prompt doesn’t appear at all, and the feature doesn’t work. Is there a special configuration required for TestFlight? Has anyone encountered this issue before? Thanks!

That's a question for Mac app (Cocoa). I want to change the standard highlighting. I thought to use tableView.selectionHighlightStyle. But there are only 2 values: .none and .regular. Cannot find how to define a custom one. So I tried a workaround: set tableView.selectionHighlightStyle to .none func tableView(_ tableView: NSTableView, viewFor tableColumn: NSTableColumn?, row: Int) -> NSView? { tableView.selectionHighlightStyle = .none keep track of previousSelection Then, in tableViewSelectionDidChange reset for previousSelection func tableViewSelectionDidChange(_ notification: Notification) { } if previousSelection >= 0 { let cellView = theTableView.rowView(atRow: previousSelection, makeIfNecessary: false) cellView?.layer?.backgroundColor = .clear } set for the selection to a custom color let cellView = theTableView.rowView(atRow: row, makeIfNecessary: false) cellView?.layer?.backgroundColor = CGColor(red: 0, green: 0, blue: 1, alpha: 0.4) previousSelection = row Result is disappointing : Even though tableView.selectionHighlightStyle is set to .none, it does overlays the cellView?.layer Is there a way to directly change the color for selection ?

Announcing the Swift Student Challenge 2026 Every year, Apple’s Swift Student Challenge celebrates the creativity and ingenuity of student developers from around the world, inviting them to use Swift and Xcode to solve real-world problems in their own communities and beyond. Learn more → https://developer.apple.com/swift-student-challenge/ Submissions for the 2026 challenge will open February 6 for three weeks, and students can prepare with new Develop in Swift tutorials and Meet with Apple code-along sessions. The Apple Developer team is here is to help you along the way - from idea to app, post your questions at any stage of your development here in this forum board or be sure to add the Swift Student Challenge tag to your technology-specific forum question. Your designs. Your apps. Your moment.

When using the new RealityKit Manipulation Component on Entities, indirect input will never translate the entity - no matter what settings are applied. Direct manipulation works as expected for both translation and rotation. Is this intended behaviour? This is different from how indirect manipulation works on Model3D. How else can we get translation from this component? visionOS 26 Beta 2 Build from macOS 26 Beta 2 and Xcode 26 Beta 2 Attached is replicable sample code, I have tried this in other projects with the same results. var body: some View { RealityView { content in // Add the initial RealityKit content if let immersiveContentEntity = try? await Entity(named: "MovieFilmReel", in: reelRCPBundle) { ManipulationComponent.configureEntity(immersiveContentEntity, allowedInputTypes: .all, collisionShapes: [ShapeResource.generateBox(width: 0.2, height: 0.2, depth: 0.2)]) immersiveContentEntity.position.y = 1 immersiveContentEntity.position.z = -0.5 var mc = ManipulationComponent() mc.releaseBehavior = .stay immersiveContentEntity.components.set(mc) content.add(immersiveContentEntity) } } }

I've suddenly started seeing hundreds of the same block of four error messages (see attached image) when running my app on my iOS device through Xcode. I've tried Cleaning the Build folder, but I keep seeing these messages in the console but can't find anything about them. Phone is running iOS 26.1. Xcode is at 16.4. Mac is on Sequoia 15.5. The app is primarily a MapKit SwiftUI based application. Messages below: Connection error: Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named com.apple.PerfPowerTelemetryClientRegistrationService was invalidated: Connection init failed at lookup with error 159 - Sandbox restriction." UserInfo={NSDebugDescription=The connection to service named com.apple.PerfPowerTelemetryClientRegistrationService was invalidated: Connection init failed at lookup with error 159 - Sandbox restriction.} (+[PPSClientDonation isRegisteredSubsystem:category:]) Permission denied: Maps / SpringfieldUsage (+[PPSClientDonation sendEventWithIdentifier:payload:]) Invalid inputs: payload={ isSPR = 0; } CAMetalLayer ignoring invalid setDrawableSize width=0.000000 height=0.000000 I'm also seeing the following error messages: CoreUI: CUIThemeStore: No theme registered with id=0

In a class, I call the following (edited to simplify, but it matches the real case). If I do this: func getData() -> someClass? { _ = someURL.startAccessingSecurityScopedResource() if let data = NSData(contentsOf: someURL as URL) { do { let unarchiver = try NSKeyedUnarchiver(forReadingFrom: data as Data) print((unarchiver.decodeObject(of: [NSArray.self, someClass.self /* and few others*/], forKey: oneKey) as? someClass)?.aProperty) if let result = unarchiver.decodeObject(of: [NSArray.self, someClass.self /* same other types*/], forKey: oneKey) as? someClass { unarchiver.finishDecoding() print("unarchived success") return result } else { unarchiver.finishDecoding() print("unarchiving failed") return someClass() } } catch { return nil } } I get a failure on log : unarchiving failed But if I comment out the print(unarchiver.decodeObject) - line 8, it works and I get unarchived success // print((unarchiver.decodeObject(of: [NSArray.self, someClass.self /* and few others*/], forKey: oneKey) as? someClass)?.aProperty) However, when I do exactly the same for another class (I've compared line by line to be sure), it works even with the print statement. What could be happening here ?

I’ve been struggling with a very frustrating issue using the new iOS 26 Swift Concurrency APIs for video processing. My pipeline reads frames using AVAssetReader, processes them via CIContext (Lanczos upscale), and then appends the result to an AVAssetWriter using the new PixelBufferReceiver. The Problem: The execution randomly stops at the ]await append(...)] call. The task suspends and never resumes. It is completely unpredictable: It might hang on the very first run, or it might work fine for 4-5 runs and then hang on the next one. It is independent of video duration: It happens with 5-second clips just as often as with long videos. No feedback from the system: There is no crash, no error thrown, and CPU usage drops to zero. The thread just stays in the suspended state indefinitely. If I manually cancel the operation and restart the VideoEngine, it usually starts working again for a few more attempts, which makes me suspect some internal resource exhaustion or a deadlock between the GPU context and the writer's input. The Code: Here is a simplified version of my processing loop: private func proccessVideoPipeline( readerOutputProvider: AVAssetReaderOutput.Provider<CMReadySampleBuffer<CMSampleBuffer.DynamicContent>>, pixelBufferReceiver: AVAssetWriterInput.PixelBufferReceiver, nominalFrameRate: Float, targetSize: CGSize ) async throws { while !Task.isCancelled, let payload = try await readerOutputProvider.next() { let sampleBufferInfo: (imageBuffer: CVPixelBuffer?, presentationTimeStamp: CMTime) = payload.withUnsafeSampleBuffer { sampleBuffer in return (sampleBuffer.imageBuffer, sampleBuffer.presentationTimeStamp) } guard let currentPixelBuffer = sampleBufferInfo.imageBuffer else { throw AsyncFrameProcessorError.missingImageBuffer } guard let pixelBufferPool = pixelBufferReceiver.pixelBufferPool else { throw NSError(domain: "PixelBufferPool", code: -1, userInfo: [NSLocalizedDescriptionKey: "No pixel buffer pool available"]) } let newPixelBuffer = try pixelBufferPool.makeMutablePixelBuffer() let newCVPixelBuffer = newPixelBuffer.withUnsafeBuffer({ $0 }) try upscale(currentPixelBuffer, outputPixelBuffer: newCVPixelBuffer, targetSize: targetSize ) let presentationTime = sampleBufferInfo.presentationTimeStamp try await pixelBufferReceiver.append(.init(unsafeBuffer: newCVPixelBuffer), with: presentationTime) } } Does anyone know how to fix it?

Hi, I am a UI designer and a total newbie with coding, so I have been using AI in Xcode to do all my coding for my personal project. Everything was working fine until this morning, when I tried to run my app in the simulator (I didn't even change any code from the last time I ran the simulator) and now the simulator is crashing and freezing and I have been trying to fix it with the AI recommendations, but it seems way too complicated for me to handle even with AI's help. I feel like I need to talk to an expert and guide me out of this hole. Please help. Thank you!

I decode an object with NSKeyedArchiver (SecureCoding): typealias BoolArray = Array<Array<Bool>> let val = decoder.decodeObject(of: NSArray.self, forKey: someKey) as? BoolArray I get the following log: *** -[NSKeyedUnarchiver validateAllowedClass:forKey:] allowed unarchiving safe plist type ''NSNumber' (0x204cdbeb8) [/System/Library/Frameworks/Foundation.framework]' for key 'NS.objects', even though it was not explicitly included in the client allowed classes set: '{( "'NSArray' (0x204cd5598) [/System/Library/Frameworks/CoreFoundation.framework]" )}'. This will be disallowed in the future. I changed by adding NSNumber.self in the list : let val = decoder.decodeObject(of: [NSArray.self, NSNumber.self], forKey: someKey) as? BoolArray No more warning in log. Is there a reason for this ?