Objective-C

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Objective-C is a programming language for writing iOS, iPad OS, and macOS apps.

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Programming Languages Resources
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"
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1.6k
Oct ’25
What is the future of Objective-C?
Will Apple continue to support it, or will we wake up one day to find that Swift is the only viable language?It's a serious question. Careers depend on it. I don't accept the "No comment" approach that Apple usually takes. It's cruel.I'm willing to put the time into learning Swift if I have to. I'm not going to do it if I don't. I want to know.Frank
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34k
Oct ’25
Called endBackgroundTask but not working
When my app enter to background, I start a background task, and when Expiration happens, I end my background task. The code likes below: backgroundTask = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{ dispatch_async(dispatch_get_main_queue(), ^{ if (backgroundTask != UIBackgroundTaskInvalid) { [[UIApplication sharedApplication] endBackgroundTask:backgroundTask]; backgroundTask = UIBackgroundTaskInvalid; [self cancel]; } }); }]; When the breakpoint is triggered at the endBackgroundTask line, I also get the following log: [BackgroundTask] Background task still not ended after expiration handlers were called: <UIBackgroundTaskInfo: 0x282d7ab40>: taskID = 36, taskName = Called by MyApp, from MyMethod, creationTime = 892832 (elapsed = 26). This app will likely be terminated by the system. Call UIApplication.endBackgroundTask(:) to avoid this. The log don't appear every time, so why is that? Is there something wrong with my code?
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3.1k
Jun ’25
UIDocumentPickerViewController provides corrupt copy of file when user taps multiple times on file
We're trying to implement a backup/restore data feature in our business productivity iPad app using UIDocumentPickerViewController and AppleArchive, but discovered odd behavior of [UIDocumentPickerViewController initForOpeningContentTypes: asCopy:YES] when reading large archive files from a USB drive. We've duplicated this behavior with iPadOS 16.6.1 and 17.7 when building our app with Xcode 15.4 targeting minimum deployment of iPadOS 16. We haven't tested this with bleeding edge iPadOS 18. Here's our Objective-C code which presents the picker: NSArray* contentTypeArray = @[UTTypeAppleArchive]; UIDocumentPickerViewController* docPickerVC = [[UIDocumentPickerViewController alloc] initForOpeningContentTypes:contentTypeArray asCopy:YES]; docPickerVC.delegate = self; docPickerVC.allowsMultipleSelection = NO; docPickerVC.shouldShowFileExtensions = YES; docPickerVC.modalPresentationStyle = UIModalPresentationPopover; docPickerVC.popoverPresentationController.sourceView = self.view; [self presentViewController:docPickerVC animated:YES completion:nil]; The UIDocumentPickerViewController remains visible until the selected external archive file has been copied from the USB drive to the app's local tmp sandbox. This may take several seconds due to the slow access speed of the USB drive. During this time the UIDocumentPickerViewController does NOT disable its tableview rows displaying files found on the USB drive. Even the most patient user will tap the desired filename a second (or third or fourth) time since the user's initial tap appears to have been ignored by UIDocumentPickerViewController, which lacks sufficient UI feedback showing it's busy copying the selected file. When the user taps the file a second time, UIDocumentPickerViewController apparently begins to copy the archive file once again. The end result is a truncated copy of the selected file based on the time between taps. For instance, a 788 MB source archive may be copied as a 56 MB file. Here, the UIDocumentPickerDelegate receives a 56 MB file instead of the original 788 MB of data. Not surprisingly, AppleArchive fails to decrypt the local copy of the archive because it's missing data. Instead of failing gracefully, AppleArchive crashes in AAArchiveStreamClose() (see forums post 765102 for details). Does anyone know if there's a workaround for this strange behavior of UIDocumentPickerViewController?
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1.1k
Sep ’25
[UIViewController willMoveToParentViewController:] provides an incorrect navStack when popping a view controller in iPadOS 18.2
The Apple documentation for [UIViewController willMoveToParentViewController:] states, Called just before the view controller is added or removed from a container view controller. Hence, the view controller being popped should appear at the top of the navStack when willMoveToParentViewController: is called. In iPadOS 16 and 17 the view controller being popped appears at the top of the navStack when willMoveToParentViewController: is called. In iPadOS 18 the view controller being popped has already been (incorrectly) removed from the navStack. We confirmed this bug using iPadOS 18.2 as well as 18.0. Our app relies upon the contents of the navStack within willMoveToParentViewController: to track the user's location within a folder hierarchy. Our app works smoothly on iPadOS 16 and 17. Conversely, our customers running iPadOS 18 have lost client data and corrupted their data folders as a result of this bug! These customers are angry -- not surprisingly, some have asked for refunds and submitted negative app reviews. Why doesn't willMoveToParentViewController: provide the correct navStack in iPadOS 18.2?
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690
Aug ’25
How to Implement Screen Mirroring in iOS for Google TV?
I am developing an iOS application that supports screen mirroring to Google TV (or Chromecast with Google TV). My goal is to mirror the iPhone/iPad screen in real time to a Google TV device. What I Have Tried So Far I have explored multiple approaches but haven't found a direct way to achieve low-latency screen mirroring. Here are some of my findings: Google Cast SDK: Google Cast SDK is primarily designed for casting media (videos, images, audio) rather than real-time mirroring. It supports custom receiver applications, but there are no direct APIs for full screen mirroring. Casting a recorded video is possible, but it introduces latency and is not real-time. ReplayKit for Screen Capture: RPScreenRecorder.shared().startCapture(handler: ...) allows capturing the iPhone screen as a video stream. However, sending this stream to Google TV in real time is a challenge. I could potentially encode the video as HLS and stream it, but the delay is significant. RTSP/UDP Streaming: Some third-party libraries support RTSP/UDP streaming for real-time screen sharing. Google TV does not natively support RTSP, making this approach difficult. My Questions: Is it possible to achieve real-time screen mirroring on Google TV using Google Cast SDK? Does Google TV support WebRTC or any low-latency streaming protocol that can be used from iOS? Are there any alternative approaches to mirror an iOS screen to Google TV with minimal latency? I would appreciate any guidance, code examples, or references to relevant documentation.
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741
Dec ’25
WiFi Connect error,NEHotspotConfigurationErrorDomain code=11
hi everybody, When I use the following code to connect to WiFi network, an error message of "error=null" or "error='Error Domain=NEHotspotConfigurationErrorDomain Code=11 "" UserInfo={NSLocalizedDescription=}' " will occur. It has been uploaded to Feedback. Feedback ID: FB16819345 (WiFi-无法加入网络) NEHotspotConfiguration *hotspotConfig = [[NEHotspotConfiguration alloc] initWithSSID:ssid passphrase:psk isWEP:NO]; [[NEHotspotConfigurationManager sharedManager] applyConfiguration:hotspotConfig completionHandler:^(NSError * _Nullable error) { }];
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Jun ’25
What's the idea behind the changes in the Objective-C flavor of the Foundation documentation?
I just noticed that when you check the online documentation for Foundation using the delicious Objective-C flavor, some values are no more the expected ones: https://developer.apple.com/documentation/foundation/filemanager/copyitem(at:to:)?language=objc#return-value true if the item was copied successfully or the file manager’s delegate stopped the operation deliberately. Returns false if an error occurred. Considering that a BOOL used to be YES or NO for the last quarter of a century, I have the following question: [Q] What is the idea behind the disturbing changes of the Objective-C documentation?
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Apr ’25
What is the correct syntax to continue in app for custom intent?
I have a custom intent. When my app is unable to complete the resolution of a parameter within the app extension, I need to be able to continue within the app. I am unable to figure out what the correct objective C syntax is to enable the execution to continue with the app. Here is what I have tried: completion([[PickWoodIntentResponse init] initWithCode:PickWoodIntentResponseCodeContinueInApp userActivity:nil]); This results in the following error: Implicit conversion from enumeration type 'enum PickWoodIntentResponseCode' to different enumeration type 'INAnswerCallIntentResponseCode' (aka 'enum INAnswerCallIntentResponseCode') I have no idea why it is referring to the enum type of 'INAnswerCallIntentResponseCode' which is unrelated to my app. I have also tried: PickWoodIntentResponse *response = [[PickWoodIntentResponse init] initWithCode:PickWoodIntentResponseCodeContinueInApp userActivity:nil]; completion(response); but that results in 2 errors: Implicit conversion from enumeration type 'enum PickWoodIntentResponseCode' to different enumeration type 'INAnswerCallIntentResponseCode' (aka 'enum INAnswerCallIntentResponseCode') and Incompatible pointer types passing 'PickWoodIntentResponse *' to parameter of type 'INStringResolutionResult *' The relevant autogenerated code provided to me with the creation of my intent is as follows: @class PickWoodIntentResponse; @protocol PickWoodIntentHandling <NSObject> - (void)resolveVarietyForPickWood:(PickWoodIntent *)intent withCompletion:(void (^)(INStringResolutionResult *resolutionResult))completion NS_SWIFT_NAME(resolveVariety(for:with:)) API_AVAILABLE(ios(13.0), macos(11.0), watchos(6.0)); @end typedef NS_ENUM(NSInteger, PickWoodIntentResponseCode) { PickWoodIntentResponseCodeUnspecified = 0, PickWoodIntentResponseCodeReady, PickWoodIntentResponseCodeContinueInApp, PickWoodIntentResponseCodeInProgress, PickWoodIntentResponseCodeSuccess, PickWoodIntentResponseCodeFailure, PickWoodIntentResponseCodeFailureRequiringAppLaunch } @interface PickWoodIntentResponse : INIntentResponse - (instancetype)init NS_UNAVAILABLE; - (instancetype)initWithCode:(PickWoodIntentResponseCode)code userActivity:(nullable NSUserActivity *)userActivity NS_DESIGNATED_INITIALIZER; @property (readonly, NS_NONATOMIC_IOSONLY) PickWoodIntentResponseCode code; @end Am I overlooking something? What would be the proper syntax to have within the completion block to satisfy the compiler?
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149
Apr ’25
Can't change iPhone watch app complication picker app name
I have an objective-c watch app and have added a swift widget style compilation to it and am having problems. The complication works fine but the name in the iPhone watch app complication picker stubbornly remains as the watchkit app name despite me trying various ways of changing it. Here are the various CF bundle name and display name values I am using: phone app values CFBundleIdentifier - com.Distribution-Systems-Associates.Tennis-Watch-v1 CFBundleName - $(PRODUCT_NAME) CFBundleDisplayName - Tennis Scorekeeper watchkit app CFBundleIdentifier - com.Distribution-Systems-Associates.Tennis-Watch-v1.watchkitapp CFBundleName - Tennis Scorekeeper CFBundleDisplayName - Tennis Scorekeeper WatchKit extension CFBundleIdentifier - com.Distribution-Systems-Associates.Tennis-Watch-v1.watchkitapp.watchkitextension CFBundleName - Tennis Scorekeeper CFBundleDisplayName - Tennis Scorekeeper __Watchkit complication __ CFBundleIdentifier - com.Distribution-Systems-Associates.Tennis-Watch-v1.watchkitapp.watchkitextension.Tennis-Watch-V1-Complication Changing the values in the complication doesn't seem to matter. Every other name in both my iPhone and watch apps are as expected. ChatGPT suggested that I try adding a localized name in the watchkit app but that didn't seem to do much of anything useful. I have run this though Chat quite a bit to see if I could get any accidental insights that way and while it has been interesting, it has also been not terribly helpful. I didn't post any of the complication code because that seems to be fine. However, I can do that if needed. The complication works as intended (starts the app). The various names everywhere else show up as intended. It's just that this one name refuses to be overridden. Thoughts?
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259
May ’25
NSTask-launch path not accessible
I'm trying to launch a command line app from my objective C application (sandboxed) using NSTask and I keep getting "launch path not accessible" Here is the path: [task setLaunchPath:@"/usr/local/bin/codeview"]; I have set the appropriate attributes for codeview and it is working perfectly when I use it from the command line and /usr/local/bin IS in the $PATH I know I have NSTask configured correctly because this WILL work: [task setLaunchPath:@"/usr/bin/hexdump"]; With the exception being that I'm using a command already in /usr/bin. But I can't copy codeview into /usr/bin due to SIPS. I've tried moving codeview to various other non-SIPS protected locations all to no avail. Must all NSTask commands come from /usr/bin? Where might I put codeview so that it can be launched. Today I'm going to use an older computer and disable SIPS to put my command in /usr/bin and see if that works. If it does. I will do it on my main machine.
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Apr ’25
Xcode 15.4: "Swift.h" file not found for simulator
I'm currently adding swift widgets to my existing ObjC project and building it for ios-simulator causes a "Swift.h" file not found error. it works without issue for device build. I see the file compiled under DerivedData at and set the Header Search Path and User Header Search Path to: $(CONFIGURATION_TEMP_DIR)/$(PROJECT_NAME).build/DerivedSources but it still doesn't work. Removing the #import "proj-Swift.h" line fixes the issues, but I need to import it to use WidgetCenter ReloadAllTimelines. I checked that the file is being generated correctly by viewing the autogenerated file and its contents. Any advice and direction would be a great help. Been stuck on this all week and I can't think of a different solution.
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Apr ’25
AVAssetWriterInputTaggedPixelBufferGroupAdaptor Hanging With Tagged Buffers
We've successfully implemented an AVAssetWriter to produce HLS streams (all code is Objective-C++ for interop with existing codebase) but are struggling to extend the operations to use tagged buffers. We're starting to wonder if the tagged buffers required for an MV-HEVC signal are fully supported when producing HLS segments in a live-stream setting. We generate a live stream of data using something like: UTType *t = [UTType typeWithIdentifier:AVFileTypeMPEG4]; m_writter = [[AVAssetWriter alloc] initWithContentType:t]; // - videoHint describes HEVC and width/height // - m_videoConfig includes compression settings and, when using MV-HEVC, // the correct keys are added (i.e. kVTCompressionPropertyKey_MVHEVCVideoLayerIDs) // The app was throwing an exception without these which was // useful to know when we got the configuration right. m_video = [[AVAssetWriterInput alloc] initWithMediaType:AVMediaTypeVideo outputSettings:m_videoConfig sourceFormatHint:videoHint]; For either path we're producing CVPixelBufferRefs that contain the raw pixel information (i.e. 32BGRA) so we use an adapter to make that as simple as possible. If we use a single view and a AVAssetWriterInputPixelBufferAdaptor things work out very well. We produce segments and the delegate is called. However, if we use the AVAssetWriterInputTaggedPixelBufferGroupAdaptor as exampled in the SideBySideToMVHEVC demo project, things go poorly. We create the tagged buffers with something like: CMTagCollectionRef collections[2]; CMTag leftTags[] = { CMTagMakeWithSInt64Value( kCMTagCategory_VideoLayerID, (int64_t)0), CMTagMakeWithSInt64Value( kCMTagCategory_StereoView, kCMStereoView_LeftEye) }; CMTagCollectionCreate( kCFAllocatorDefault, leftTags, 2, &(collections[0]) ); CMTag rightTags[] = { CMTagMakeWithSInt64Value( kCMTagCategory_VideoLayerID, (int64_t)1), CMTagMakeWithSInt64Value( kCMTagCategory_StereoView, kCMStereoView_RightEye) }; CMTagCollectionCreate( kCFAllocatorDefault, rightTags, 2, &(collections[1]) ); CFArrayRef tagCollections = CFArrayCreate( kCFAllocatorDefault, (const void **)collections, 2, &kCFTypeArrayCallBacks ); CVPixelBufferRef buffers[] = {*b, *alt}; CFArrayRef b = CFArrayCreate( kCFAllocatorDefault, (const void **)buffers, 2, &kCFTypeArrayCallBacks ); CMTaggedBufferGroupRef bufferGroup; OSStatus res = CMTaggedBufferGroupCreate( kCFAllocatorDefault, tagCollections, b, &bufferGroup ); Perhaps there's something about this OBJC code that I've buggered up? Hopefully! Anyways, when I submit this tagged bugger group to the adaptor: if (![mvVideoAdapter appendTaggedPixelBufferGroup:bufferGroup withPresentationTime:pts]) { // report error... } Appending does not raise any errors - eventually it just hangs on us and we never return from it... Real Issue: So either: The delegate assigned to the AVAssetWriter doesn't fire its assetWriter callback which should produce the segments The adapter hangs on the appendTaggedPixelBufferGroup before a segment is ready to be completed (but succeeds for a number of buffer groups before this happens). This is the same delegate class that's assigned to the non multi view code path if MV-HEVC is turned off which works perfectly.
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Apr ’25
Query GPU metrics
Hello! I'm a developer working on a plugin for the Elgato Stream Deck, called GPU Metrics. The plugin currently only works on Windows but I'd like to bring it to macOS. However, based on forum posts I've read (and StackOverflow) there isn't a very clear path to query GPU metrics like usage, temperature, used GPU memory, and power consumption. There are some tools out there that do similar things, but I wanted to see what would be the recommendation from Apple's engineering team to get this data via a public API. Requirements: Access GPU utilization, temperature, memory usage, power usage C/C++ based API for querying the metrics so I can expose the data to JavaScript via Node Addon No need to compatibile with Intel-based Macs, as Apple silicon will be fine for now Plugin GitHub Thank you! Noah
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May ’25
When using WKWebView in iOS 18.0 (Xcode 16.2) to open a local H5 page, the request for server resources cannot carry cookies.
In our project, we download H5 resources to the local device and then open the H5 pages through WKWebView(-loadFileURL:allowingReadAccessToURL:). When the H5 pages request server resources, cookies are required. Before opening the H5 page, we set the required cookies in the WKHTTPCookieStore using the setCookie method. Additionally, we set the allowFileAccessFromFileURLs and allowUniversalAccessFromFileURLs properties for the WebView. On other mobile phones, the cookies can be carried normally. However, on mobile phones running the iOS 18.0 system, the cookies cannot be carried. Moreover, this problem only emerged after we upgraded Xcode to version 16.2. We've also tried injecting cookies via JavaScript, but it didn't work(document.cookie = xx=${xx}; path=/; expires=weekday, xx jan xxxx xx:xx:xx GMT; Domain=example.com; Secure; SameSite=None ;). Can anyone help me on this? Thanks in advance.
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May ’25
-applicationDockMenu: method on NSApplicationDelegate doesn't work when attached to debugger
When I add a simple menu to the dock via the NSApplicationDelegate method -applicationDockMenu: and run the app from Xcode it doesn't work. -(NSMenu*)applicationDockMenu:(NSApplication*)sender { NSMenu *dockMenu = [self buildDockMenu]; if (dockMenu != nil) { NSLog(@"Returning dock menu."); return dockMenu; } else { NSLog(@"Not ready to build dock menu"); return nil; } } When I run the app, my main app window shows up but nothing logs out in -applicationDockMenu: until I click outside my app's window (so if I click the desktop background, or a Finder window, or whatever). Then after I click outside my app's main window this logs out: Returning dock menu. The "Not ready to build dock menu" message does not log out. But...when I right click on the dock icon, the menu doesn't show up. But if I stop the app from Xcode and just run it not attached to the debugger, the dock menu does show up. But this makes the debugging/testing situation not ideal.
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180
May ’25
Objective-C Literals inside a Swift Package
I have a Swift Package that contains an Objective-C target. The target contains Objective-C literals but unfortunately the compiler says "Initializer element is not a compile-time constant", what am I doing wrong? Based on the error triggering in the upper half, I take it that objc_array_literals is on. My target definition looks like: .target( name: "MyTarget", path: "Sources/MySourcesObjC", publicHeadersPath: "include", cxxSettings: [ .unsafeFlags("-fobjc-constant-literals") ] ), I believe Objective-C literals are enabled since a long time but I still tried passing in the -fobjc-constant-literals flag and no luck. To be clear I'm not interested in a run-time initialization, I really want it to be compile time. Does anyone know what I can do?
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May ’25
How to Create Applications with Objective-C Without ARC
I've been teaching myself Objective-C and I wanted to start creating projects that don't use ARC to become better at memory management and learn how it all works. I've been attempting to build and run applications, but I'm not really sure where to start as modern iOS development is used with Swift and memory management is handled. Is there any way to create modern applications that use Objective-C, UIKit, and not use ARC?
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May ’25
Programming Languages Resources
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"
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1.6k
Activity
Oct ’25
What is the future of Objective-C?
Will Apple continue to support it, or will we wake up one day to find that Swift is the only viable language?It's a serious question. Careers depend on it. I don't accept the "No comment" approach that Apple usually takes. It's cruel.I'm willing to put the time into learning Swift if I have to. I'm not going to do it if I don't. I want to know.Frank
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23
Boosts
1
Views
34k
Activity
Oct ’25
Get Serial Number From Device?
I have a project that need to get serial number and network SSID. I have looking anywhere to get those 2 value but no luck to find it. is there anyway i can get those information from the device?
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3
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0
Views
1.3k
Activity
Sep ’25
Called endBackgroundTask but not working
When my app enter to background, I start a background task, and when Expiration happens, I end my background task. The code likes below: backgroundTask = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{ dispatch_async(dispatch_get_main_queue(), ^{ if (backgroundTask != UIBackgroundTaskInvalid) { [[UIApplication sharedApplication] endBackgroundTask:backgroundTask]; backgroundTask = UIBackgroundTaskInvalid; [self cancel]; } }); }]; When the breakpoint is triggered at the endBackgroundTask line, I also get the following log: [BackgroundTask] Background task still not ended after expiration handlers were called: <UIBackgroundTaskInfo: 0x282d7ab40>: taskID = 36, taskName = Called by MyApp, from MyMethod, creationTime = 892832 (elapsed = 26). This app will likely be terminated by the system. Call UIApplication.endBackgroundTask(:) to avoid this. The log don't appear every time, so why is that? Is there something wrong with my code?
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3
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0
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3.1k
Activity
Jun ’25
UIDocumentPickerViewController provides corrupt copy of file when user taps multiple times on file
We're trying to implement a backup/restore data feature in our business productivity iPad app using UIDocumentPickerViewController and AppleArchive, but discovered odd behavior of [UIDocumentPickerViewController initForOpeningContentTypes: asCopy:YES] when reading large archive files from a USB drive. We've duplicated this behavior with iPadOS 16.6.1 and 17.7 when building our app with Xcode 15.4 targeting minimum deployment of iPadOS 16. We haven't tested this with bleeding edge iPadOS 18. Here's our Objective-C code which presents the picker: NSArray* contentTypeArray = @[UTTypeAppleArchive]; UIDocumentPickerViewController* docPickerVC = [[UIDocumentPickerViewController alloc] initForOpeningContentTypes:contentTypeArray asCopy:YES]; docPickerVC.delegate = self; docPickerVC.allowsMultipleSelection = NO; docPickerVC.shouldShowFileExtensions = YES; docPickerVC.modalPresentationStyle = UIModalPresentationPopover; docPickerVC.popoverPresentationController.sourceView = self.view; [self presentViewController:docPickerVC animated:YES completion:nil]; The UIDocumentPickerViewController remains visible until the selected external archive file has been copied from the USB drive to the app's local tmp sandbox. This may take several seconds due to the slow access speed of the USB drive. During this time the UIDocumentPickerViewController does NOT disable its tableview rows displaying files found on the USB drive. Even the most patient user will tap the desired filename a second (or third or fourth) time since the user's initial tap appears to have been ignored by UIDocumentPickerViewController, which lacks sufficient UI feedback showing it's busy copying the selected file. When the user taps the file a second time, UIDocumentPickerViewController apparently begins to copy the archive file once again. The end result is a truncated copy of the selected file based on the time between taps. For instance, a 788 MB source archive may be copied as a 56 MB file. Here, the UIDocumentPickerDelegate receives a 56 MB file instead of the original 788 MB of data. Not surprisingly, AppleArchive fails to decrypt the local copy of the archive because it's missing data. Instead of failing gracefully, AppleArchive crashes in AAArchiveStreamClose() (see forums post 765102 for details). Does anyone know if there's a workaround for this strange behavior of UIDocumentPickerViewController?
Replies
9
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0
Views
1.1k
Activity
Sep ’25
[UIViewController willMoveToParentViewController:] provides an incorrect navStack when popping a view controller in iPadOS 18.2
The Apple documentation for [UIViewController willMoveToParentViewController:] states, Called just before the view controller is added or removed from a container view controller. Hence, the view controller being popped should appear at the top of the navStack when willMoveToParentViewController: is called. In iPadOS 16 and 17 the view controller being popped appears at the top of the navStack when willMoveToParentViewController: is called. In iPadOS 18 the view controller being popped has already been (incorrectly) removed from the navStack. We confirmed this bug using iPadOS 18.2 as well as 18.0. Our app relies upon the contents of the navStack within willMoveToParentViewController: to track the user's location within a folder hierarchy. Our app works smoothly on iPadOS 16 and 17. Conversely, our customers running iPadOS 18 have lost client data and corrupted their data folders as a result of this bug! These customers are angry -- not surprisingly, some have asked for refunds and submitted negative app reviews. Why doesn't willMoveToParentViewController: provide the correct navStack in iPadOS 18.2?
Replies
2
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0
Views
690
Activity
Aug ’25
How to Implement Screen Mirroring in iOS for Google TV?
I am developing an iOS application that supports screen mirroring to Google TV (or Chromecast with Google TV). My goal is to mirror the iPhone/iPad screen in real time to a Google TV device. What I Have Tried So Far I have explored multiple approaches but haven't found a direct way to achieve low-latency screen mirroring. Here are some of my findings: Google Cast SDK: Google Cast SDK is primarily designed for casting media (videos, images, audio) rather than real-time mirroring. It supports custom receiver applications, but there are no direct APIs for full screen mirroring. Casting a recorded video is possible, but it introduces latency and is not real-time. ReplayKit for Screen Capture: RPScreenRecorder.shared().startCapture(handler: ...) allows capturing the iPhone screen as a video stream. However, sending this stream to Google TV in real time is a challenge. I could potentially encode the video as HLS and stream it, but the delay is significant. RTSP/UDP Streaming: Some third-party libraries support RTSP/UDP streaming for real-time screen sharing. Google TV does not natively support RTSP, making this approach difficult. My Questions: Is it possible to achieve real-time screen mirroring on Google TV using Google Cast SDK? Does Google TV support WebRTC or any low-latency streaming protocol that can be used from iOS? Are there any alternative approaches to mirror an iOS screen to Google TV with minimal latency? I would appreciate any guidance, code examples, or references to relevant documentation.
Replies
1
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1
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741
Activity
Dec ’25
WiFi Connect error,NEHotspotConfigurationErrorDomain code=11
hi everybody, When I use the following code to connect to WiFi network, an error message of "error=null" or "error='Error Domain=NEHotspotConfigurationErrorDomain Code=11 "" UserInfo={NSLocalizedDescription=}' " will occur. It has been uploaded to Feedback. Feedback ID: FB16819345 (WiFi-无法加入网络) NEHotspotConfiguration *hotspotConfig = [[NEHotspotConfiguration alloc] initWithSSID:ssid passphrase:psk isWEP:NO]; [[NEHotspotConfigurationManager sharedManager] applyConfiguration:hotspotConfig completionHandler:^(NSError * _Nullable error) { }];
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15
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0
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680
Activity
Jun ’25
Cannot find 'TARGET_OS_SIMULATOR' in the scope
I tried to build the project with Xcode 16.3 and I initially got an error that TARGET_IPHONE_SIMULATOR does not exist, then I changed this flag to TARGET_OS_SIMULATOR, but it did not solve the problem
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2
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0
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2k
Activity
Apr ’25
Decode Base64 String in Objective c
I want decoded my base64 string and want to create image from it. NSData *data = [NSData dataWithBytes:bpData.rt_wav.data length:sizeof(bpData.rt_wav.data)]; NSMutableString *baseString = [data base64Encoding]; UIImage *image = [UIImage imageWithData:data];
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116
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Apr ’25
What's the idea behind the changes in the Objective-C flavor of the Foundation documentation?
I just noticed that when you check the online documentation for Foundation using the delicious Objective-C flavor, some values are no more the expected ones: https://developer.apple.com/documentation/foundation/filemanager/copyitem(at:to:)?language=objc#return-value true if the item was copied successfully or the file manager’s delegate stopped the operation deliberately. Returns false if an error occurred. Considering that a BOOL used to be YES or NO for the last quarter of a century, I have the following question: [Q] What is the idea behind the disturbing changes of the Objective-C documentation?
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5
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259
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Apr ’25
What is the correct syntax to continue in app for custom intent?
I have a custom intent. When my app is unable to complete the resolution of a parameter within the app extension, I need to be able to continue within the app. I am unable to figure out what the correct objective C syntax is to enable the execution to continue with the app. Here is what I have tried: completion([[PickWoodIntentResponse init] initWithCode:PickWoodIntentResponseCodeContinueInApp userActivity:nil]); This results in the following error: Implicit conversion from enumeration type 'enum PickWoodIntentResponseCode' to different enumeration type 'INAnswerCallIntentResponseCode' (aka 'enum INAnswerCallIntentResponseCode') I have no idea why it is referring to the enum type of 'INAnswerCallIntentResponseCode' which is unrelated to my app. I have also tried: PickWoodIntentResponse *response = [[PickWoodIntentResponse init] initWithCode:PickWoodIntentResponseCodeContinueInApp userActivity:nil]; completion(response); but that results in 2 errors: Implicit conversion from enumeration type 'enum PickWoodIntentResponseCode' to different enumeration type 'INAnswerCallIntentResponseCode' (aka 'enum INAnswerCallIntentResponseCode') and Incompatible pointer types passing 'PickWoodIntentResponse *' to parameter of type 'INStringResolutionResult *' The relevant autogenerated code provided to me with the creation of my intent is as follows: @class PickWoodIntentResponse; @protocol PickWoodIntentHandling <NSObject> - (void)resolveVarietyForPickWood:(PickWoodIntent *)intent withCompletion:(void (^)(INStringResolutionResult *resolutionResult))completion NS_SWIFT_NAME(resolveVariety(for:with:)) API_AVAILABLE(ios(13.0), macos(11.0), watchos(6.0)); @end typedef NS_ENUM(NSInteger, PickWoodIntentResponseCode) { PickWoodIntentResponseCodeUnspecified = 0, PickWoodIntentResponseCodeReady, PickWoodIntentResponseCodeContinueInApp, PickWoodIntentResponseCodeInProgress, PickWoodIntentResponseCodeSuccess, PickWoodIntentResponseCodeFailure, PickWoodIntentResponseCodeFailureRequiringAppLaunch } @interface PickWoodIntentResponse : INIntentResponse - (instancetype)init NS_UNAVAILABLE; - (instancetype)initWithCode:(PickWoodIntentResponseCode)code userActivity:(nullable NSUserActivity *)userActivity NS_DESIGNATED_INITIALIZER; @property (readonly, NS_NONATOMIC_IOSONLY) PickWoodIntentResponseCode code; @end Am I overlooking something? What would be the proper syntax to have within the completion block to satisfy the compiler?
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149
Activity
Apr ’25
Can't change iPhone watch app complication picker app name
I have an objective-c watch app and have added a swift widget style compilation to it and am having problems. The complication works fine but the name in the iPhone watch app complication picker stubbornly remains as the watchkit app name despite me trying various ways of changing it. Here are the various CF bundle name and display name values I am using: phone app values CFBundleIdentifier - com.Distribution-Systems-Associates.Tennis-Watch-v1 CFBundleName - $(PRODUCT_NAME) CFBundleDisplayName - Tennis Scorekeeper watchkit app CFBundleIdentifier - com.Distribution-Systems-Associates.Tennis-Watch-v1.watchkitapp CFBundleName - Tennis Scorekeeper CFBundleDisplayName - Tennis Scorekeeper WatchKit extension CFBundleIdentifier - com.Distribution-Systems-Associates.Tennis-Watch-v1.watchkitapp.watchkitextension CFBundleName - Tennis Scorekeeper CFBundleDisplayName - Tennis Scorekeeper __Watchkit complication __ CFBundleIdentifier - com.Distribution-Systems-Associates.Tennis-Watch-v1.watchkitapp.watchkitextension.Tennis-Watch-V1-Complication Changing the values in the complication doesn't seem to matter. Every other name in both my iPhone and watch apps are as expected. ChatGPT suggested that I try adding a localized name in the watchkit app but that didn't seem to do much of anything useful. I have run this though Chat quite a bit to see if I could get any accidental insights that way and while it has been interesting, it has also been not terribly helpful. I didn't post any of the complication code because that seems to be fine. However, I can do that if needed. The complication works as intended (starts the app). The various names everywhere else show up as intended. It's just that this one name refuses to be overridden. Thoughts?
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3
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259
Activity
May ’25
NSTask-launch path not accessible
I'm trying to launch a command line app from my objective C application (sandboxed) using NSTask and I keep getting "launch path not accessible" Here is the path: [task setLaunchPath:@"/usr/local/bin/codeview"]; I have set the appropriate attributes for codeview and it is working perfectly when I use it from the command line and /usr/local/bin IS in the $PATH I know I have NSTask configured correctly because this WILL work: [task setLaunchPath:@"/usr/bin/hexdump"]; With the exception being that I'm using a command already in /usr/bin. But I can't copy codeview into /usr/bin due to SIPS. I've tried moving codeview to various other non-SIPS protected locations all to no avail. Must all NSTask commands come from /usr/bin? Where might I put codeview so that it can be launched. Today I'm going to use an older computer and disable SIPS to put my command in /usr/bin and see if that works. If it does. I will do it on my main machine.
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6
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232
Activity
Apr ’25
Xcode 15.4: "Swift.h" file not found for simulator
I'm currently adding swift widgets to my existing ObjC project and building it for ios-simulator causes a "Swift.h" file not found error. it works without issue for device build. I see the file compiled under DerivedData at and set the Header Search Path and User Header Search Path to: $(CONFIGURATION_TEMP_DIR)/$(PROJECT_NAME).build/DerivedSources but it still doesn't work. Removing the #import "proj-Swift.h" line fixes the issues, but I need to import it to use WidgetCenter ReloadAllTimelines. I checked that the file is being generated correctly by viewing the autogenerated file and its contents. Any advice and direction would be a great help. Been stuck on this all week and I can't think of a different solution.
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141
Activity
Apr ’25
AVAssetWriterInputTaggedPixelBufferGroupAdaptor Hanging With Tagged Buffers
We've successfully implemented an AVAssetWriter to produce HLS streams (all code is Objective-C++ for interop with existing codebase) but are struggling to extend the operations to use tagged buffers. We're starting to wonder if the tagged buffers required for an MV-HEVC signal are fully supported when producing HLS segments in a live-stream setting. We generate a live stream of data using something like: UTType *t = [UTType typeWithIdentifier:AVFileTypeMPEG4]; m_writter = [[AVAssetWriter alloc] initWithContentType:t]; // - videoHint describes HEVC and width/height // - m_videoConfig includes compression settings and, when using MV-HEVC, // the correct keys are added (i.e. kVTCompressionPropertyKey_MVHEVCVideoLayerIDs) // The app was throwing an exception without these which was // useful to know when we got the configuration right. m_video = [[AVAssetWriterInput alloc] initWithMediaType:AVMediaTypeVideo outputSettings:m_videoConfig sourceFormatHint:videoHint]; For either path we're producing CVPixelBufferRefs that contain the raw pixel information (i.e. 32BGRA) so we use an adapter to make that as simple as possible. If we use a single view and a AVAssetWriterInputPixelBufferAdaptor things work out very well. We produce segments and the delegate is called. However, if we use the AVAssetWriterInputTaggedPixelBufferGroupAdaptor as exampled in the SideBySideToMVHEVC demo project, things go poorly. We create the tagged buffers with something like: CMTagCollectionRef collections[2]; CMTag leftTags[] = { CMTagMakeWithSInt64Value( kCMTagCategory_VideoLayerID, (int64_t)0), CMTagMakeWithSInt64Value( kCMTagCategory_StereoView, kCMStereoView_LeftEye) }; CMTagCollectionCreate( kCFAllocatorDefault, leftTags, 2, &(collections[0]) ); CMTag rightTags[] = { CMTagMakeWithSInt64Value( kCMTagCategory_VideoLayerID, (int64_t)1), CMTagMakeWithSInt64Value( kCMTagCategory_StereoView, kCMStereoView_RightEye) }; CMTagCollectionCreate( kCFAllocatorDefault, rightTags, 2, &(collections[1]) ); CFArrayRef tagCollections = CFArrayCreate( kCFAllocatorDefault, (const void **)collections, 2, &kCFTypeArrayCallBacks ); CVPixelBufferRef buffers[] = {*b, *alt}; CFArrayRef b = CFArrayCreate( kCFAllocatorDefault, (const void **)buffers, 2, &kCFTypeArrayCallBacks ); CMTaggedBufferGroupRef bufferGroup; OSStatus res = CMTaggedBufferGroupCreate( kCFAllocatorDefault, tagCollections, b, &bufferGroup ); Perhaps there's something about this OBJC code that I've buggered up? Hopefully! Anyways, when I submit this tagged bugger group to the adaptor: if (![mvVideoAdapter appendTaggedPixelBufferGroup:bufferGroup withPresentationTime:pts]) { // report error... } Appending does not raise any errors - eventually it just hangs on us and we never return from it... Real Issue: So either: The delegate assigned to the AVAssetWriter doesn't fire its assetWriter callback which should produce the segments The adapter hangs on the appendTaggedPixelBufferGroup before a segment is ready to be completed (but succeeds for a number of buffer groups before this happens). This is the same delegate class that's assigned to the non multi view code path if MV-HEVC is turned off which works perfectly.
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121
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Apr ’25
Query GPU metrics
Hello! I'm a developer working on a plugin for the Elgato Stream Deck, called GPU Metrics. The plugin currently only works on Windows but I'd like to bring it to macOS. However, based on forum posts I've read (and StackOverflow) there isn't a very clear path to query GPU metrics like usage, temperature, used GPU memory, and power consumption. There are some tools out there that do similar things, but I wanted to see what would be the recommendation from Apple's engineering team to get this data via a public API. Requirements: Access GPU utilization, temperature, memory usage, power usage C/C++ based API for querying the metrics so I can expose the data to JavaScript via Node Addon No need to compatibile with Intel-based Macs, as Apple silicon will be fine for now Plugin GitHub Thank you! Noah
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143
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May ’25
When using WKWebView in iOS 18.0 (Xcode 16.2) to open a local H5 page, the request for server resources cannot carry cookies.
In our project, we download H5 resources to the local device and then open the H5 pages through WKWebView(-loadFileURL:allowingReadAccessToURL:). When the H5 pages request server resources, cookies are required. Before opening the H5 page, we set the required cookies in the WKHTTPCookieStore using the setCookie method. Additionally, we set the allowFileAccessFromFileURLs and allowUniversalAccessFromFileURLs properties for the WebView. On other mobile phones, the cookies can be carried normally. However, on mobile phones running the iOS 18.0 system, the cookies cannot be carried. Moreover, this problem only emerged after we upgraded Xcode to version 16.2. We've also tried injecting cookies via JavaScript, but it didn't work(document.cookie = xx=${xx}; path=/; expires=weekday, xx jan xxxx xx:xx:xx GMT; Domain=example.com; Secure; SameSite=None ;). Can anyone help me on this? Thanks in advance.
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2
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280
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May ’25
-applicationDockMenu: method on NSApplicationDelegate doesn't work when attached to debugger
When I add a simple menu to the dock via the NSApplicationDelegate method -applicationDockMenu: and run the app from Xcode it doesn't work. -(NSMenu*)applicationDockMenu:(NSApplication*)sender { NSMenu *dockMenu = [self buildDockMenu]; if (dockMenu != nil) { NSLog(@"Returning dock menu."); return dockMenu; } else { NSLog(@"Not ready to build dock menu"); return nil; } } When I run the app, my main app window shows up but nothing logs out in -applicationDockMenu: until I click outside my app's window (so if I click the desktop background, or a Finder window, or whatever). Then after I click outside my app's main window this logs out: Returning dock menu. The "Not ready to build dock menu" message does not log out. But...when I right click on the dock icon, the menu doesn't show up. But if I stop the app from Xcode and just run it not attached to the debugger, the dock menu does show up. But this makes the debugging/testing situation not ideal.
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3
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180
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May ’25
Objective-C Literals inside a Swift Package
I have a Swift Package that contains an Objective-C target. The target contains Objective-C literals but unfortunately the compiler says "Initializer element is not a compile-time constant", what am I doing wrong? Based on the error triggering in the upper half, I take it that objc_array_literals is on. My target definition looks like: .target( name: "MyTarget", path: "Sources/MySourcesObjC", publicHeadersPath: "include", cxxSettings: [ .unsafeFlags("-fobjc-constant-literals") ] ), I believe Objective-C literals are enabled since a long time but I still tried passing in the -fobjc-constant-literals flag and no luck. To be clear I'm not interested in a run-time initialization, I really want it to be compile time. Does anyone know what I can do?
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292
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May ’25
How to Create Applications with Objective-C Without ARC
I've been teaching myself Objective-C and I wanted to start creating projects that don't use ARC to become better at memory management and learn how it all works. I've been attempting to build and run applications, but I'm not really sure where to start as modern iOS development is used with Swift and memory management is handled. Is there any way to create modern applications that use Objective-C, UIKit, and not use ARC?
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341
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May ’25