Hello everyone.
macOS, IOBluetooth framework.
My goal is to create a temporary SDP service. According to the documentation, by default a temporary service is created (aka Persistent = NO), which is deleted after the application is closed.
The documentation also mentions the IOBluetoothRemoveServiceWithRecordHandle function for forced removal of the service. This function is deprecated and is currently unavailable. I guesse that it has been replaced by the IOBluetoothSDPServiceRecord.removeServiceRecord method.
The essence of the problem is that the server is not deleted either using removeServiceRecord or even after app closing.
That is, if you create several services and try to delete them, they will remain alive. Only turning Bluetooth off and on in the OS helps.
I tested all versions of macOS starting with Monteray. The same behavior.
for (int i = 0; i < 10; i++) {
service = [IOBluetoothSDPServiceRecord publishedServiceRecordWithDictionary:dictionary];
if (!service) {
NSLog(@"Failed to create service");
}
else
{
[service getRFCOMMChannelID:&channelID];
[service getServiceRecordHandle:&serverHandle];
NSLog(@"A new service has been created handle=%u, channelID=%hhu", serverHandle, channelID);
if (service.removeServiceRecord != kIOReturnSuccess) {
NSLog(@"Failed to delete service");
}
//service.release;
service = nil;
}
}
Can someone confirm this behavior? And is there a solution?
A minimal test example is available at the link
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Hi Apple Developer Community,
I'm facing a crash when updating an array of tuples from both a background thread and the main thread simultaneously. Here's a simplified version of the code in a macOS app using AppKit:
class ViewController: NSViewController {
var mainthreadButton = NSButton(title: "test", target: self, action: nil)
var numbers = Array(repeating: (dim: Int, key: String)(0, "default"), count: 1000)
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(mainthreadButton)
mainthreadButton.translatesAutoresizingMaskIntoConstraints = false
mainthreadButton.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
mainthreadButton.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
mainthreadButton.widthAnchor.constraint(equalToConstant: 100).isActive = true
mainthreadButton.heightAnchor.constraint(equalToConstant: 100).isActive = true
mainthreadButton.target = self
mainthreadButton.action = #selector(arraytest(_:))
}
@objc func arraytest(_ sender: NSButton) {
print("array update started")
// Background update
DispatchQueue.global().async {
for i in 0..<1000 {
self.numbers[i].dim = i
}
}
// Main thread update
var sum = 0
for i in 0..<1000 {
numbers[i].dim = i + 1
sum += numbers[i].dim
print("test \(sum)")
}
mainthreadButton.title = "test = \(sum)"
}
}
This results in a crash with the following message:
malloc: double free for ptr 0x136040c00
malloc: *** set a breakpoint in malloc_error_break to debug
What's interesting:
This crash only happens when the tuple contains a String ((dim: Int, key: String))
If I change the tuple type to use two Int values ((dim: Int, key: Int)), the crash does not occur
My Questions:
Why does mutating an array of tuples containing a String crash when accessed from multiple threads?
Why is the crash avoided when the tuple contains only primitive types like Int?
Is there an underlying memory management issue with value types containing reference types like String?
Any explanation about this behavior and best practices for thread-safe mutation of such arrays would be much appreciated.
Thanks in advance!
I’ve been struggling with this issue for a long time. When I try to archive my app to submit it to the App Store, I encounter two errors:
Linker command failed with exit code 1 (use -v to see invocation)
Linker command failed with exit code 1 (use -v to see invocation)
Topic:
Programming Languages
SubTopic:
Swift
I can't find the arm_neon.h header file in macOS 15.6.1
This header file defines NEON intrinsics.
and yeah, swift vaguely is reminiscent of a programming language I developed, but
I want swift To do
return if (var blah:Int32 == 43){
blah = blah2;
}
your welcome !! thank me on my new accounting job lol =/
basically I want to return conditional statements for a private reason
We are Java application developers and we have a question regarding camera access via WebRTC on iPadOS. Specifically, on iPadOS 17.1, we are encountering an issue when trying to access the camera via the WKWebView API in the Chrome browser, where an error occurs and the camera capture fails. Our investigation suggests that device access through the navigator.mediaDevices property via the WKWebView API may not work in Chrome. However, it works as expected in the Safari browser, leading us to wonder if this is a Chrome-specific limitation, or if it's due to an iPadOS setting or specification.
At this point, we are unsure if this issue is related to the WKWebView and WebRTC specifications on iPadOS 17.1, or if there are specific limitations in Chrome. We would appreciate any insights or solutions regarding camera access in iPadOS 17.1 with WKWebView and WebRTC, especially in relation to Chrome.
Hello,
I asked this question on 9th March but was asked to provide a project file and can't edit the original post. Please find the original question below and please find the new test project file at https://we.tl/t-fqAu8FrgUw.
I have a json array showing in Xcode debugger (from the line "print(dataString)"):
Optional("[{\"id\":\"8e8tcssu4u2hn7a71tkveahjhn8xghqcfkwf1bzvtrw5nu0b89w\",\"name\":\"Test name 0\",\"country\":\"Test country 0\",\"type\":\"Test type 0\",\"situation\":\"Test situation 0\",\"timestamp\":\"1546848000\"},{\"id\":\"z69718a1a5z2y5czkwrhr1u37h7h768v05qr3pf1h4r4yrt5a68\",\"name\":\"Test name 1\",\"country\":\"Test country 1\",\"type\":\"Test type 1\",\"situation\":\"Test situation 1\",\"timestamp\":\"1741351615\"},{\"id\":\"fh974sv586nhyysbhg5nak444968h7hgcgh6yw0usbvcz9b0h69\",\"name\":\"Test name 2\",\"country\":\"Test country 2\",\"type\":\"Test type 2\",\"situation\":\"Test situation 2\",\"timestamp\":\"1741351603\"},{\"id\":\"347272052385993\",\"name\":\"Test name 3\",\"country\":\"Test country 3\",\"type\":\"Test type 3\",\"situation\":\"Test situation 3\",\"timestamp\":\"1741351557\"}]")
But my JSON decoder is throwing the catch error "Error in JSON parsing"
This is the code:
let urlString = "https://www.notafunnyname.com/jsonmockup.php"
let url = URL(string: urlString)
guard url != nil else {
return
}
let session = URLSession.shared
let dataTask = session.dataTask(with: url!) { (data, response, error) in
var dataString = String(data: data!, encoding: String.Encoding.utf8)
print(dataString)
if error == nil && data != nil {
// Parse JSON
let decoder = JSONDecoder()
do {
let newsFeed = try decoder.decode(NewsFeed.self, from: data!)
print(newsFeed)
print(error)
}
catch{
print("Error in JSON parsing")
}
}
}
// Make the API Call
dataTask.resume()
}
And this is my Codable file NewsFeed.swift:
struct NewsFeed: Codable {
var id: String
var name: String
var country: String
var type: String
var overallrecsit: String
var dlastupd: String
var doverallrecsit: String
}
Please do you know why the parsing may be failing? Is it significant that in the debugging window the JSON is displaying backslashes before the quotation marks?
Thank you for any pointers :-)
Topic:
Programming Languages
SubTopic:
Swift
I have an xcode project which has both cpp and swift code. In one of my usecase I am passing primitive type variables from swift to cpp by reference( primitives types list here as per the new cpp-swift interop documentation)
swift code:
// primitive check code:Bool
var x : Bool = true
// When we are passing a variable as a Reference, we need to use explicitly use'&'
student.PassBoolAsReferenceType (&x) // interop call to cpp code
print (x)
Cpp code:
void
Student::PassBoolAsReferenceType(bool &pValue) noexcept
{
std::cout << pValue << std::endl;
pValue = false;
}
The above code fails during compilation with no clear error message "Command SwiftCompile failed with a nonzero exit code"
However, all the other primitive types that I tested worked for the above code like Int, Float, Double etc. Only the Bool interop fails. Can someone explain why is it not possible for bool? I m using the new interop introduced in swift 5.9.
I've narrowed down my question after many rabbit holes - how can C++ code open any view in Swift. I can call functions in swift from C++ (works great), but not async or main actor (or actor at all) functions. And if I'm not mistaken all views are actors if not main actors? When calling from C+ I think its necessary that the first view be the main actor?
I've implemented the code from the WWDC23 C++ interop video (Zoe's image picker) where I made a view in a struct, and just want to call it and let the view do the work.
The compiler immediately gives me 'cannot expose main actors to C++'. If I'm not mistaken, doesn't this block the opening of any kind of swift view from C++? Hopefully I'm missing something obvious, which is likely :)
In Zoe's code was his entry point into the program still Swift and not actually C++ app?
Thanks!
Thanks!
Topic:
Programming Languages
SubTopic:
Swift
I notice that Swift Data type's hashValue collision when first 80 byte of data and data length are same because of the Implementation only use first 80 bytes to compute the hash.
https://web.archive.org/web/20120605052030/https://opensource.apple.com/source/CF/CF-635.21/CFData.c
also, even if hash collision on the situation like this, I can check data is really equal or not by ==
does there any reason for this implementation(only use 80 byte of data to make hashValue)?
test code is under below
let dataArray: [UInt8] = [
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00
]
var dataArray1: [UInt8] = dataArray
var dataArray2: [UInt8] = dataArray
dataArray1.append(contentsOf: [0x00, 0x00, 0x00, 0x00])
dataArray2.append(contentsOf: [0xff, 0xff, 0xff, 0xff])
let data1 = Data(dataArray1)
let data2 = Data(dataArray2) // Only last 4 byte differs
print(data1.hashValue)
print(data2.hashValue)
print(data1.hashValue == data2.hashValue) // true
print(data1 == data2) // false
How can I calculate polynomial coefficients for Tone Curve points:
// • Red channel: (0, 0), (60, 39), (128, 128), (255, 255)
// • Green channel: (0, 0), (63, 50), (128, 128), (255, 255)
// • Blue channel: (0, 0), (60, 47), (119, 119), (255, 255)
CIFilter:
func colorCrossPolynomial(inputImage: CIImage) -> CIImage? {
let colorCrossPolynomial = CIFilter.colorCrossPolynomial()
let redfloatArr: [CGFloat] = [1, 1, 1, 1, 0, 0, 0, 0, 0, 0]
let greenfloatArr: [CGFloat] = [0, 1, 1, 0, 0, 0, 0, 0, 0, 1]
let bluefloatArr: [CGFloat] = [0, 0, 1, 0, 0, 0, 0, 1, 1, 0]
colorCrossPolynomial.inputImage = inputImage
colorCrossPolynomial.blueCoefficients = CIVector(values: bluefloatArr, count: bluefloatArr.count)
colorCrossPolynomial.redCoefficients = CIVector(values: redfloatArr, count: redfloatArr.count)
colorCrossPolynomial.greenCoefficients = CIVector(values: greenfloatArr, count: greenfloatArr.count)
return colorCrossPolynomial.outputImage
}
Hi I'm new here - I'm trying to learn Swift and SwiftUI.
Tried on PluralSight and Udemy but they have been outdated and thus hard to follow.
So after finding Apples own guides I felt relieved and happy, but now I'm stuck again.
After they've updated Xcode to use #Preview instead of PreviewProvider it's hard to follow along on their tutorial.
Does anyone know of good resources to study SwiftUI? Or know if apple plan to update their tutorials any time soon?
I'm here now if anyone's interested or it's useful information: https://developer.apple.com/tutorials/app-dev-training/managing-state-and-life-cycle
I am currently encountering two deprecated errors in my code. Could someone please identify the issues with the code?
Errors:
'init(coordinateRegion:interactionModes:showsUserLocation:userTrackingMode:annotationItems:annotationContent:)' was deprecated in iOS 17.0: Use Map initializers that take a MapContentBuilder instead.
'MapAnnotation' was deprecated in iOS 17.0: Use Annotation along with Map initializers that take a MapContentBuilder instead.
Code:
// MARK: - Stores Map (Dynamic)
struct StoresMapView: View {
@State private var storeLocations: [StoreLocation] = []
@State private var region = MKCoordinateRegion(
center: CLLocationCoordinate2D(latitude: -31.95, longitude: 115.86),
span: MKCoordinateSpan(latitudeDelta: 0.5, longitudeDelta: 0.5)
)
var body: some View {
Map(coordinateRegion: $region, interactionModes: .all, annotationItems: storeLocations) { store in
MapAnnotation(coordinate: CLLocationCoordinate2D(latitude: store.latitude, longitude: store.longitude)) {
VStack(spacing: 4) {
Image(systemName: "leaf.circle.fill")
.font(.title)
.foregroundColor(.green)
Text(store.name)
.font(.caption)
.fixedSize()
}
}
}
.onAppear(perform: loadStoreData)
.navigationTitle("Store Locator")
}
private func loadStoreData() {
guard let url = URL(string: "https://example.com/cop092/StoreLocations.json") else { return }
URLSession.shared.dataTask(with: url) { data, _, _ in
if let data = data, let decoded = try? JSONDecoder().decode([StoreLocation].self, from: data) {
DispatchQueue.main.async {
self.storeLocations = decoded
if let first = decoded.first {
self.region.center = CLLocationCoordinate2D(latitude: first.latitude, longitude: first.longitude)
}
}
}
}.resume()
}
}
I’m working with Swift and ran into an issue when using the contains(_:) method on an array. The following code works fine:
let result = ["hello", "world"].contains(Optional("hello")) // ✅ Works fine
But when I try to use the same contains method with the array declared in a separate variable, I get a compile-time error:
let stringArray = ["hello", "world"]
let result = stringArray.contains(Optional("hello")) // ❌ Compile-time error
Both examples seem conceptually similar, but the second one causes a compile-time error, while the first one works fine.
I understand that when comparing an optional value (Optional("hello")) with a non-optional value ("hello"), Swift automatically promotes the non-optional value to an optional (i.e., "hello" becomes Optional("hello")).
🔗 reference
What I don’t understand is why the first code works but the second one doesn’t, even though both cases involve comparing an optional value with a non-optional value. I know that there are different ways to resolve this, like using nil coalescing or optional binding, but what I’m really looking for is a detailed explanation of why this issue occurs at the compile-time level.
Can anyone explain the underlying reason for this behavior?
Consider this Swift struct:
public struct Example
{
public func foo(callback: ()->Void)
{
....
}
public func blah(i: Int)
{
....
}
....
}
Using Swift/C++ interop, I can create Example objects and call methods like blah. But I can't call foo because Swift/C++ interop doesn't currently support passing closures (right?).
On the other hand, Swift/objC does support passing objC blocks to Swift functions. But I can't use that here because Example is a Swift struct, not a class. So I could change it to a class, and update everything to work with reference rather than value semantics; but then I also have to change the objC++ code to create the object and call its methods using objC syntax. I'd like to avoid that.
Is there some hack that I can use to make this possible? I'm hoping that I can wrap a C++ std::function in some sort of opaque wrapper and pass that to swift, or something.
Thanks for any suggestions!
I am creating a macOs SwiftUI document based app, and I am struggling with the Window sizes and placements. Right now by default, a normal window has the minimize and full screen options which makes the whole window into full screen mode.
However, I don't want to do this for my app. I want to only allow to fill the available width and height, i.e. exclude the status bar and doc when the user press the fill window mode, and also restrict to resize the window beyond a certain point ( which ideally to me is 1200 x 700 because I am developing on macbook air 13.3-inch in which it looks ideal, but resizing it below that makes the entire content inside messed up ).
I want something like this below instead of the default full screen green
When the user presses the button, it should position centered with perfect aspect ratio from my content ( or the one I want like 1200 x 700 ) and can be able to click again to fill the available width and height excluding the status bar and docs.
Here is my entire @main code :-
@main
struct PhiaApp: App {
@NSApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
var body: some Scene {
DocumentGroup(newDocument: PhiaProjectDocument()) { file in
ContentView(
document: file.$document,
rootURL: file.fileURL
)
.configureEditorWindow(disableCapture: true)
.background(AppColors.background)
.preferredColorScheme(.dark)
}
.windowStyle(.hiddenTitleBar)
.windowToolbarStyle(.unified)
.defaultLaunchBehavior(.suppressed)
Settings {
SettingsView()
}
}
}
struct WindowAccessor: NSViewRepresentable {
var callback: (NSWindow?) -> Void
func makeNSView(context: Context) -> NSView {
let view = NSView()
DispatchQueue.main.async { [weak view] in
callback(view?.window)
}
return view
}
func updateNSView(_ nsView: NSView, context: Context) { }
}
extension View {
func configureEditorWindow(disableCapture: Bool = true) -> some View {
self.background(
WindowAccessor { window in
guard let window else { return }
if let screen = window.screen ?? NSScreen.main {
let visible = screen.visibleFrame
window.setFrame(visible, display: true)
window.minSize = visible.size
}
window.isMovable = true
window.isMovableByWindowBackground = false
window.sharingType = disableCapture ? .captureBlocked : .captureAllowed
}
)
}
}
This is a basic setup I did for now, this automatically fills the available width and height on launch, but user can resize and can go beyond my desired min width and height which makes the entire content inside messy.
As I said, I want a native way of doing this, respect the content aspect ratio, don't allow to enter full screen mode, only be able to fill the available width and height excluding the status bar and doc, also don't allow to resize below my desired width and height.
谁能告诉我为什么?
“[正在运行] swift ”d:\vscode object\swift object\ceshi.swift”
JIT 会话错误:未找到符号:[ $ss 27_allocateUninitializedArrayySayxG_BptBwlFyp_Tg5 ]
未能具体化符号: { (main, { main, $sSa 12_endMutationyyF, $ss 5print_9separator10terminatoryypd_S2StFfA0_, $ss 5print_9separator10terminatoryypd_S2StFfA1_, $ss 27_finalizeUninitializedArrayySayxGABnlF }) }
[完成] 在 0.47 秒内退出并带有 code=4294967295”
当“Swift for Windows”在 VSCode for Windows 上运行时。
路径为 true,“Package-swift-lsp: Path”为 true。
谁能告诉我为什么?
Topic:
Programming Languages
SubTopic:
Swift
I have implemented the Game Center for authentication and saving player's game data. Both authentication and saving player's data works correctly all the time, but there is a problem with fetching and loading the data.
The game works like this:
At the startup, I start the authentication
After the player successfully logs in, I start loading the player's data by calling fetchSavedGames method
If a game data exists for the player, I receive a list of SavedGame object containing the player's data
The problem is that after I uninstall the game and install it again, sometimes the SavedGame list is empty(step 3). But if I don't uninstall the game and reopen the game, this process works fine.
Here's the complete code of Game Center implementation:
class GameCenterHandler {
public func signIn() {
GKLocalPlayer.local.authenticateHandler = { viewController, error in
if let viewController = viewController {
viewController.present(viewController, animated: false)
return
}
if error != nil {
// Player could not be authenticated.
// Disable Game Center in the game.
return
}
// Auth successfull
self.load(filename: "TestFileName")
}
}
public func save(filename: String, data: String) {
if GKLocalPlayer.local.isAuthenticated {
GKLocalPlayer.local.saveGameData(Data(data.utf8), withName: filename) { savedGame, error in
if savedGame != nil {
// Data saved successfully
}
if error != nil {
// Error in saving game data!
}
}
} else {
// Error in saving game data! User is not authenticated"
}
}
public func load(filename: String) {
if GKLocalPlayer.local.isAuthenticated {
GKLocalPlayer.local.fetchSavedGames { games, error in
if let game = games?.first(where: {$0.name == filename}){
game.loadData { data, error in
if data != nil {
// Data loaded successfully
}
if error != nil {
// Error in loading game data!
}
}
} else {
// Error in loading game data! Filename not found
}
}
} else {
// Error in loading game data! User is not authenticated
}
}
}
I have also added Game Center and iCloud capabilities in xcode. Also in the iCloud section, I selected the iCloud Documents and added a container.
I found a simillar question here but it doesn't make things clearer.
PLATFORM AND VERSION
iOS
Development environment: Xcode 26, macOS 26
Run-time configuration: iOS 18 and up
DESCRIPTION OF PROBLEM
I am on the beta version of os 26 for both Xcode and macOS. When I try to run my project, which has the Swift OpenAPI Generator from apple, it gives the error "unsupported configuration: the aggregate target 'OpenAPIGenerator' has package dependencies, but targets that build for different platforms depend on it"
STEPS TO REPRODUCE
Install macOS 26 and Xcode 26 and try running an iOS app built for iOS 18.0 and up wit the OpenAPIGenerator package on a physical iPhone running iOS 26
Topic:
Programming Languages
SubTopic:
Swift
I have a Settings class that conform to the TestProtocol. From the function of the protocol I need to call the setString function and this function needs to be on the MainActor. Is there a way of make this work in Swift6, without making the protocol functions running on @MainActor
The calls are as follows:
class Settings: TestProtocol{
var value:String = ""
@MainActor func setString( _ string:String ){
value = string
}
func passString(string: String) {
Task{
await setString(string)
}
}
}
protocol TestProtocol{
func passString( string:String )
}