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"

I have a custom object which gets passed back to the main app from XPC. I whitelist it like so: NSSet *expectedClass = [NSSet setWithObjects:[NSArray class], [MyCustomClass class], nil]; [interface setClasses:expectedClass forSelector:@selector(myMethodNameHere:withCompletion:) argumentIndex:0 ofReply:YES]; Now my custom class conforms to NSSecureCoding. It does have an array property of another custom class. @property (nonatomic,readonly) NSArray *arraypropertyOfOtherClass; Which is decoded in -initWithCoder: using: -decodeArrayOfObjectsOfClasses:forKey: Now on macOS Tahoe this is all walking fine. But I just tested on macOS Monterey and I get the following error: Exception: decodeObjectForKey: too many nested collections when explicitly decoding a single collection. How should I handle this for earlier versions of macOS?

To establish a privileged helper daemon from a command line app to handle actions requiring root privileges I still use the old way of SMJobBless. But this is deprecated since OSX 10.13 and I want to finally update it to the new way using SMAppService. As I'm concerned with securing it against malicious exploits, do you have a recommended up-to-date implementation in Objective-C establishing a privileged helper and verifying it is only used by my signed app? I've seen the suggestion in the documentation to use SMAppService, but couldn't find a good implementation covering security aspects. My old implementation in brief is as follows: bool runJobBless () { // check if already installed NSFileManager* filemgr = [NSFileManager defaultManager]; if ([filemgr fileExistsAtPath:@"/Library/PrivilegedHelperTools/com.company.Helper"] && [filemgr fileExistsAtPath:@"/Library/LaunchDaemons/com.company.Helper.plist"]) { // check helper version to match the client // ... return true; } // create authorization reference AuthorizationRef authRef; OSStatus status = AuthorizationCreate (NULL, kAuthorizationEmptyEnvironment, kAuthorizationFlagDefaults, &authRef); if (status != errAuthorizationSuccess) return false; // obtain rights to install privileged helper AuthorizationItem authItem = { kSMRightBlessPrivilegedHelper, 0, NULL, 0 }; AuthorizationRights authRights = { 1, &authItem }; AuthorizationFlags flags = kAuthorizationFlagDefaults | kAuthorizationFlagInteractionAllowed | kAuthorizationFlagPreAuthorize | kAuthorizationFlagExtendRights; status = AuthorizationCopyRights (authRef, &authRights, kAuthorizationEmptyEnvironment, flags, NULL); if (status != errAuthorizationSuccess) return false; // SMJobBless does it all: verify helper against app and vice-versa, place and load embedded launchd.plist in /Library/LaunchDaemons, place executable in /Library/PrivilegedHelperTools CFErrorRef cfError; if (!SMJobBless (kSMDomainSystemLaunchd, (CFStringRef)@"com.company.Helper", authRef, &cfError)) { // check helper version to match the client // ... return true; } else { CFBridgingRelease (cfError); return false; } } void connectToHelper () { // connect to helper via XPC NSXPCConnection* c = [[NSXPCConnection alloc] initWithMachServiceName:@"com.company.Helper.mach" options:NSXPCConnectionPrivileged]; c.remoteObjectInterface = [NSXPCInterface interfaceWithProtocol:@protocol (SilentInstallHelperProtocol)]; [c resume]; // call function on helper and wait for completion dispatch_semaphore_t semaphore = dispatch_semaphore_create (0); [[c remoteObjectProxy] callFunction:^() { dispatch_semaphore_signal (semaphore); }]; dispatch_semaphore_wait (semaphore, dispatch_time (DISPATCH_TIME_NOW, 10 * NSEC_PER_SEC)); dispatch_release (semaphore); [c invalidate]; [c release]; }

Looking to update one of my apps that uses SKStoreReviewController +requestReview (deprecated) to AppStore.requestReview(in:) umm...I have a few of questions... Why is an NSViewController parameter required? It's really not so uncommon for an AppKit app to just use NSWindowController with a window that does not use NSViewController... It should be possible to present the review request in a standalone alert (attached to a window is preferred IMO but it still should be possible to ask in separate window). 3)...why Swift..(err nevermind) Ideally: AppStore requestReview should take a NSWindow parameter but that parameter should be optional. If nil the request should be presented in a standalone window (like an alert). If non nil..present as a sheet on the window. Why a view controller? Maybe I'm missing something.

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

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?

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFString timeIntervalSinceReferenceDate]: unrecognized selector sent to instance 0x115fadbc0' *** First throw call stack: (0x1940bd8c8 0x1910097c4 0x194159838 0x19403a4f8 0x1940423a0 0x1e42cb9a8 0x1e42ce220 0x106f02c08 0x1080a461c 0x1080be2b0 0x1080acb2c 0x1080ad7b4 0x1080b9b00 0x1080b91a4 0x1eecdb3b8 0x1eecda8c0) libc++abi: terminating due to uncaught exception of type NSException InputAnalytics called timeIntervalSinceReferenceDate in dispatch_sync.The display issue of the call stack occurs in two stages: keyboard input analysis and folding the keyboard. After adding protection to NSString, it can function normally, but I want to know the reason #import "NSString+Safe.h" @implementation NSString (Safe) - (NSTimeInterval)timeIntervalSinceReferenceDate { return 0; } - (NSTimeInterval)timeIntervalSinceDate:(NSDate *)date { return 0; } @end

I can compile this #import <Cocoa/Cocoa.h> @interface AppDelegate : NSObject <NSApplicationDelegate> @property (strong) NSWindow *window; @property (strong) NSSlider *slider; @end @implementation AppDelegate - (void)applicationDidFinishLaunching:(NSNotification *)notification { // Window size NSRect frame = NSMakeRect(0, 0, 400, 300); NSUInteger style = NSWindowStyleMaskTitled | NSWindowStyleMaskClosable | NSWindowStyleMaskResizable; self.window = [[NSWindow alloc] initWithContentRect:frame styleMask:style backing:NSBackingStoreBuffered defer:NO]; [self.window setTitle:@"Centered Slider Example"]; [self.window makeKeyAndOrderFront:nil]; // Slider size CGFloat sliderWidth = 200; CGFloat sliderHeight = 32; CGFloat windowWidth = self.window.frame.size.width; CGFloat windowHeight = self.window.frame.size.height; CGFloat sliderX = (windowWidth - sliderWidth) / 2; CGFloat sliderY = (windowHeight - sliderHeight) / 2; self.slider = [[NSSlider alloc] initWithFrame:NSMakeRect(sliderX, sliderY, sliderWidth, sliderHeight)]; [self.slider setMinValue:0]; [self.slider setMaxValue:100]; [self.slider setDoubleValue:50]; [self.window.contentView addSubview:self.slider]; } @end int main(int argc, const char * argv[]) { @autoreleasepool { NSApplication *app = [NSApplication sharedApplication]; AppDelegate *delegate = [[AppDelegate alloc] init]; [app setDelegate:delegate]; [app run]; } return 0; } with (base) johnzhou@Johns-MacBook-Pro liquidglasstest % clang -framework Foundation -framework AppKit testobjc.m and get this neat liquid glass effect: https://github.com/user-attachments/assets/4199493b-6011-4ad0-9c9f-25db8585e547 However if I use pyobjc to make an equivalent import sys from Cocoa import ( NSApplication, NSApp, NSWindow, NSSlider, NSMakeRect, NSWindowStyleMaskTitled, NSWindowStyleMaskClosable, NSWindowStyleMaskResizable, NSBackingStoreBuffered, NSObject ) class AppDelegate(NSObject): def applicationDidFinishLaunching_(self, notification): # Create the main window window_size = NSMakeRect(0, 0, 400, 300) style = NSWindowStyleMaskTitled | NSWindowStyleMaskClosable | NSWindowStyleMaskResizable self.window = NSWindow.alloc().initWithContentRect_styleMask_backing_defer_( window_size, style, NSBackingStoreBuffered, False ) self.window.setTitle_("Centered Slider Example") self.window.makeKeyAndOrderFront_(None) # Slider size and positioning slider_width = 200 slider_height = 32 window_width = self.window.frame().size.width window_height = self.window.frame().size.height slider_x = (window_width - slider_width) / 2 slider_y = (window_height - slider_height) / 2 self.slider = NSSlider.alloc().initWithFrame_(NSMakeRect(slider_x, slider_y, slider_width, slider_height)) self.slider.setMinValue_(0) self.slider.setMaxValue_(100) self.slider.setDoubleValue_(50) self.window.contentView().addSubview_(self.slider) if __name__ == "__main__": app = NSApplication.sharedApplication() delegate = AppDelegate.alloc().init() app.setDelegate_(delegate) app.run() I get a result shown at https://github.com/user-attachments/assets/7da022bc-122b-491d-9e08-030dcb9337c3 which does not have the new liquid glass effect. Why is this? Is this perhaps related to the requirement that you must compile on latest Xcode as indicated in the docs? Why, is the compiler doing some magic?

I am encountering a critical issue where a custom background image on a UIToolbar fails to display when the app is built with Xcode 26 and run on iOS 26 beta. The exact same implementation works perfectly on iOS 18 and earlier versions. We first attempted to use the legacy setBackgroundImage method, which fails to render the image on iOS 26: // 1. Get Navigation Bar and set basic properties UINavigationBar* navBar = self.navigationBar; navBar.hidden = NO; navBar.translucent = NO; // 2. Setup the UIToolbar instance UIToolbar *toolBar = [[UIToolbar alloc] initWithFrame:navBar.bounds]; toolBar.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth; // 3. Set the resizable image (This image does not appear on iOS 26) UIImage* imagePortrait = [UIImage imageNamed:@"nav_bg"]; UIEdgeInsets insets = UIEdgeInsetsMake(0.f, 6.f, 0.f, 6.f); [toolBar setBackgroundImage:[imagePortrait resizableImageWithCapInsets:insets] forToolbarPosition:UIToolbarPositionAny barMetrics:UIBarMetricsDefault]; We then migrated to the recommended modern UIToolbarAppearance to solve this, but the issue persists: // 1. Prepare Image UIImage* imagePortrait = [UIImage imageNamed:@"nav_bg"]; // Insets are applied via resizableImageWithCapInsets: (not shown in this snippet but implied) // 2. Configure UIToolbarAppearance UIToolbarAppearance *appearance = [[UIToolbarAppearance alloc] init]; appearance.backgroundImage = imagePortrait; // The image is correctly loaded (not nil) // 3. Apply the Appearance toolBar.standardAppearance = appearance; // We also applied to scrollEdgeAppearance and compactAppearance. Any information or recommended workarounds for displaying a custom background image on UIToolbar in the latest iOS 26 would be highly appreciated.

Hello, I'm currently trying to make a collaborative app. But it just works only on Reality View, when I tried to use Compositor Layer like below, the personas disappeared. ImmersiveSpace(id: "ImmersiveSpace-Metal") { CompositorLayer(configuration: MetalLayerConfiguration()) { layerRenderer in SpatialRenderer_InitAndRun(layerRenderer) } } Is there any potential solution too see Personas in Metal view? Thanks in advance!

I keep getting the following error when trying to run Passkey sign in on macOS. Told not to present authorization sheet: Error Domain=com.apple.AuthenticationServicesCore.AuthorizationError Code=1 "(null)" ASAuthorizationController credential request failed with error: Error Domain=com.apple.AuthenticationServices.AuthorizationError Code=1004 "(null)" This is the specific error. Application with identifier a is not associated with domain b I have config the apple-app-site-association link and use ?mode=developer Could there be any reason for this?

Greetings, With MacOS 15 Sequoia, Apple updated key-value-observations in such a way, that an unremoved observation by a now deallocated object will no longer cause an exception, when the observed object triggers said observation. While this is fundamentally a positive change, the issue comes with the fact, that this change affects systems based on the version of their operating system and not the version of the operating system of the build system. Many of our customers use old operating system versions and old hardware - meaning they can't easily update. Since we need to use up to date Xcode versions to develop for newer systems, our developers tend to have rather new OS versions. This means, that we are increasingly facing bugs which only happen in customer systems but not in most developer (or QA) systems. Currently, we still can use earlier OS versions with Xcode to fix these bugs, but once the used Xcode versions no longer support MacOS 14 or below this will become a major hurdle. Are there known solutions to this issue? We are currently attempting to swizzle observer adding and removal in order to fix the problem for old systems as well, but this has proven to be quite difficult and unstable. Since any weakly held property in the middle of an observation keypath can cause crashes, one would have to split up observations into multiple subobservations, which is less simple than it sounds, due to custom implementations of addObserver (such as there seems to be in array controller proxies) and collection operators. Thanks for any suggestions!

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?

3 I am working on an application to get when input audio device is being used. Basically I want to know the application using the microphone (built-in or external) This app runs on macOS. For Mac versions starting from Sonoma I can use this code: int getAudioProcessPID(AudioObjectID process) { pid_t pid; if (@available(macOS 14.0, *)) { constexpr AudioObjectPropertyAddress prop { kAudioProcessPropertyPID, kAudioObjectPropertyScopeGlobal, kAudioObjectPropertyElementMain }; UInt32 dataSize = sizeof(pid); OSStatus error = AudioObjectGetPropertyData(process, &amp;prop, 0, nullptr, &amp;dataSize, &amp;pid); if (error != noErr) { return -1; } } else { // Pre sonoma code goes here } return pid; } which works. However, kAudioProcessPropertyPID was added in macOS SDK 14.0. Does anyone know how to achieve the same functionality on previous versions?

When the app launches, it assigns the correct string stored in NSUserDefaults to the instance variable (serverAddress) of type NSString.
Afterwards, when the app transitions to a suspended state and receives a VoIP Push notification approximately 4 hours later, causing the app to enter the background state, referencing the value of serverAddress may result in it showing as &lt;NSMallocBlock: 0x106452d60&gt; even though it hasn't been deallocated. This does not occur every time. The specific class definitions are as follows. @implementation NewPAPEOPLEClient
{
    NSString* serverAddress;
    NSString* apiKey;
    dispatch_semaphore_t lock;
    NSMutableArray* errCallID;
} #define PREF_STR(key)  [[NSUserDefaults standardUserDefaults] stringForKey:(key) The global instance variable (serverAddress) is set with the following value when the application starts: serverAddress = PREF_STR(@"APP_CONTACT_SERVICE_SERVER_ADDRESS") Based on the above, please answer the following questions. (1) If the instance variable's value becomes &lt;NSMallocBlock: 0x106452d60&gt;, does that mean the memory area has been released? (2) Can the memory area of an instance variable be automatically released without being explicitly released?
 Can an instance variable of type NSString that is not autoreleased be automatically released? (3) Please tell me how to prevent the memory area from being automatically released. Will using retain prevent automatic release?

Hi everyone, I'm encountering a behaviour related to Secure Event Input on macOS and wanted to understand if it's expected or if there's a recommended approach to handle it. Scenario: App A enables secure input using EnableSecureEventInput(). While secure input is active, App A launches App B using NSWorkspace or similar. App B launches successfully, but it does not receive foreground focus — it starts in the background. The system retains focus on App A, seemingly to preserve the secure input session. Observed Behavior: From what I understand, macOS prevents app switching during Secure Event Input to avoid accidental or malicious focus stealing (e.g., to prevent UI spoofing during password entry). So: Input focus remains locked to App A. App B runs but cannot become frontmost unless the secure input session ends or App B is brought to the frontmost by manual intervention or by running a terminal script. This is consistent with system security behaviour, but it presents a challenge when App A needs to launch and hand off control to another app. Questions: Is this behaviour officially documented anywhere? Is there a recommended pattern for safely transferring focus to another app while Secure Event Input is active? Would calling DisableSecureEventInput() just before launching App B be the appropriate (and safe) solution? Or is there a better way to defer the transition? Thanks in advance for any clarification or advice.

I have a standard Mac project created using Xcode templates with Storyboard. I manually removed the window from the Storyboard file and use ViewController.h as the base class for other ViewControllers. I create new windows and ViewControllers programmatically, implementing the UI entirely through code. However, I've discovered that on all macOS versions prior to macOS 26 beta, the application would trigger automatic termination due to App Nap under certain circumstances. The specific steps are: Close the application window (the application doesn't exit immediately at this point) Click on other windows or the desktop, causing the application to lose focus (though this description might not be entirely accurate - the app might have already lost focus when the window closed, but the top menu bar still shows the current application immediately after window closure) The application automatically terminates In previous versions, I worked around this issue by manually executing [[NSApplication sharedApplication] run]; to create an additional main event loop, keeping the application active (although I understand this isn't an ideal approach). However, in macOS 26 beta, I've found that calling [[NSApplication sharedApplication] run]; causes all NSButton controls I created in the window to become unresponsive to click events, though they still respond to mouse enter events. Through recent research, I've learned that the best practice for preventing App Nap automatic termination is to use [[NSProcessInfo processInfo] disableAutomaticTermination:@"User interaction required"]; to increment the automatic termination reference count. My questions are: Why did calling [[NSApplication sharedApplication] run]; work properly on macOS versions prior to 15.6.1? Why does calling [[NSApplication sharedApplication] run]; in macOS 26 beta cause buttons to become unresponsive to click events?

Hi, I have just implemented an Audio Unit v3 host. AgsAudioUnitPlugin *audio_unit_plugin; AVAudioUnitComponentManager *audio_unit_component_manager; NSArray<AVAudioUnitComponent *> *av_component_arr; AudioComponentDescription description; guint i, i_stop; if(!AGS_AUDIO_UNIT_MANAGER(audio_unit_manager)){ return; } audio_unit_component_manager = [AVAudioUnitComponentManager sharedAudioUnitComponentManager]; /* effects */ description = (AudioComponentDescription) {0,}; description.componentType = kAudioUnitType_Effect; av_component_arr = [audio_unit_component_manager componentsMatchingDescription:description]; i_stop = [av_component_arr count]; for(i = 0; i < i_stop; i++){ ags_audio_unit_manager_load_component(audio_unit_manager, (gpointer) av_component_arr[i]); } /* instruments */ description = (AudioComponentDescription) {0,}; description.componentType = kAudioUnitType_MusicDevice; av_component_arr = [audio_unit_component_manager componentsMatchingDescription:description]; i_stop = [av_component_arr count]; for(i = 0; i < i_stop; i++){ ags_audio_unit_manager_load_component(audio_unit_manager, (gpointer) av_component_arr[i]); } But this doesn't show me Audio Unit v2 plugins, why? regards, Joël

Hi, I just started to develop audio unit hosting support in my application. Offline rendering seems to work except that I hear no output, but why? I suspect with the player goes something wrong. I connect to CoreAudio in a different location in the code. Here are some error messages I faced so far: 2025-08-14 19:42:04.132930+0200 com.gsequencer.GSequencer[34358:18611871] [avae] AVAudioEngineGraph.mm:4668 Can't retrieve source node to play sequence because there is no output node! 2025-08-14 19:42:04.151171+0200 com.gsequencer.GSequencer[34358:18611871] [avae] AVAudioEngineGraph.mm:4668 Can't retrieve source node to play sequence because there is no output node! 2025-08-14 19:43:08.344530+0200 com.gsequencer.GSequencer[34358:18614927] AUAudioUnit.mm:1417 Cannot set maximumFramesToRender while render resources allocated. 2025-08-14 19:43:08.346583+0200 com.gsequencer.GSequencer[34358:18614927] [avae] AVAEInternal.h:104 [AVAudioSequencer.mm:121:-[AVAudioSequencer(AVAudioSequencer_Player) startAndReturnError:]: (impl->Start()): error -10852 ** (<unknown>:34358): WARNING **: 19:43:08.346: error during audio sequencer start - -10852 I have implemented an AVAudioEngine based AudioUnit host. Here I instantiate player and effect: /* audio engine */ audio_engine = [[AVAudioEngine alloc] init]; fx_audio_unit_audio->audio_engine = (gpointer) audio_engine; av_format = (AVAudioFormat *) fx_audio_unit_audio->av_format; /* av audio player node */ av_audio_player_node = [[AVAudioPlayerNode alloc] init]; /* av audio unit */ av_audio_unit_effect = [[AVAudioUnitEffect alloc] initWithAudioComponentDescription:[((AVAudioUnitComponent *) AGS_AUDIO_UNIT_PLUGIN(base_plugin)->component) audioComponentDescription]]; av_audio_unit = (AVAudioUnit *) av_audio_unit_effect; fx_audio_unit_audio->av_audio_unit = av_audio_unit; /* audio sequencer */ av_audio_sequencer = [[AVAudioSequencer alloc] initWithAudioEngine:audio_engine]; fx_audio_unit_audio->av_audio_sequencer = (gpointer) av_audio_sequencer; /* output node */ [[AVAudioOutputNode alloc] init]; /* audio player and audio unit */ [audio_engine attachNode:av_audio_player_node]; [audio_engine attachNode:av_audio_unit]; [audio_engine connect:av_audio_player_node to:av_audio_unit format:av_format]; [audio_engine connect:av_audio_unit to:[audio_engine outputNode] format:av_format]; ns_error = NULL; [audio_engine enableManualRenderingMode:AVAudioEngineManualRenderingModeOffline format:av_format maximumFrameCount:buffer_size error:&ns_error]; if(ns_error != NULL && [ns_error code] != noErr){ g_warning("enable manual rendering mode error - %d", [ns_error code]); } ns_error = NULL; [[av_audio_unit AUAudioUnit] allocateRenderResourcesAndReturnError:&ns_error]; if(ns_error != NULL && [ns_error code] != noErr){ g_warning("Audio Unit allocate render resources returned error - ErrorCode %d", [ns_error code]); } Then I render in a dedicated thread. ns_error = NULL; [audio_engine startAndReturnError:&ns_error]; if(ns_error != NULL && [ns_error code] != noErr){ g_warning("error during audio engine start - %d", [ns_error code]); } [av_audio_sequencer prepareToPlay]; ns_error = NULL; [av_audio_sequencer startAndReturnError:&ns_error]; if(ns_error != NULL && [ns_error code] != noErr){ g_warning("error during audio sequencer start - %d", [ns_error code]); } [av_audio_player_node play]; while(is_running){ /* pre sync */ /* IO buffers */ av_output_buffer = (AVAudioPCMBuffer *) scope_data->av_output_buffer; av_input_buffer = (AVAudioPCMBuffer *) scope_data->av_input_buffer; /* fill input buffer */ /* schedule av input buffer */ frame_position = 0; // (gint64) ((note_offset * absolute_delay) + delay_counter) * buffer_size; av_audio_player_node = (AVAudioPlayerNode *) fx_audio_unit_audio->av_audio_player_node; AVAudioTime *av_audio_time = [[AVAudioTime alloc] initWithHostTime:frame_position sampleTime:frame_position atRate:((double) samplerate)]; [av_audio_player_node scheduleBuffer:av_input_buffer atTime:av_audio_time options:0 completionHandler:nil]; /* render */ ns_error = NULL; status = [audio_engine renderOffline:AGS_FX_AUDIO_UNIT_AUDIO_FIXED_BUFFER_SIZE toBuffer:av_output_buffer error:&ns_error]; if(ns_error != NULL && [ns_error code] != noErr){ g_warning("render offline error - %d", [ns_error code]); } } regards, Joël

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?