Hello,
I am getting an error message "Cannot convert value of type 'URLSessionDataTask' to expected argument type 'Data'" for the last line of this code. Please can you tell me what the problem is? Thank you
struct Item : Codable {
var id: String
var name: String
var country: String
var type: String
var overallrecsit: String
var dlastupd: String
var doverallrecsit: String
}
let url = URL(string:"https://www.TEST_URL.com/api_ios.php")
let json = try? JSONDecoder().decode(Item.self, from: URLSession.shared.dataTask(with: url!))
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I have been trying to integrate a UIKit view into SwiftUI, specifically a WKWebView. However, I keep encountering a does not conform to protocol error.
Here's my code:
import SwiftUI
import WebKit
struct SimpleWebView: View {
var body: some View {
WebViewContainerRepresentable()
.edgesIgnoringSafeArea(.all)
}
}
struct WebViewContainerRepresentable: UIViewRepresentable {
typealias UIViewType = WKWebView
func makeUIView(context: Context) -> WKWebView {
let webView = WKWebView()
if let url = Bundle.main.url(forResource: "index", withExtension: "html") {
webView.loadFileURL(url, allowingReadAccessTo: url.deletingLastPathComponent())
}
return webView
}
func updateUIView(_ uiView: WKWebView, context: Context) {
// Updates not required for this use case
}
}
I tried this with other views as well, and it turns out this is not WKWebView-specific.
The minimum deployment version is iOS 15.
Any help would be much appreciated. Let me know if I need to add any more information.
我的应用是在mac intel时发生这个问题,从dump看程序一直卡在mmap_locked,不知要怎么修改
程序dump如下
amaran.txt
Topic:
Programming Languages
SubTopic:
General
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?
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
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()
}
}
Hi,
I am exploring Closures and trying to understand how they works. Closure have a special key feature that they can capture the context of the variables/constants from surroundings, once captured we can still use them inside the closure even if the scope in which they are defined does not exist.
I want to understand the lifecycle of captured variable/constant i.e., where are these captured variables stored and when these get created and destroyed.
How is memory managed for captured variables or constants in a closure, depending on whether they are value types or reference types?
Topic:
Programming Languages
SubTopic:
Swift
In scope of one of our project we've faced an issue with constant crashes when integrating C++ library in Swift code using Swift/C++ interoperability.
Investigating the root causes of the issue we've discovered that with new version of Swift bug was introduced.
Long story short: for strings bigger than 27 symbols memory is feed incorrectly that causes the crashes.
By creating this post I wanted to draw community's attention to the problem and promote it to be solved quicker as for now it is not addressed.
I noticed that when I enter the fully immersive view and then click the X button below the window, the immersive space remains active, and the only way to dismiss it is to click the digital crown. On other apps (Disney+ for example), closing out of the main window while in immersive mode also closes out the immersive space. I tried applying an onDisappear modifier to the the Modules view with a dismissImmersiveSpace, but that doesn't appear to do anything.
Any help would be appreciated.
For my app I've created a Dictionary that I want to persist using AppStorage
In order to be able to do this, I added RawRepresentable conformance for my specific type of Dictionary. (see code below)
typealias ScriptPickers = [Language: Bool]
extension ScriptPickers: @retroactive RawRepresentable where Key == Language, Value == Bool {
public init?(rawValue: String) {
guard let data = rawValue.data(using: .utf8),
let result = try? JSONDecoder().decode(ScriptPickers.self, from: data)
else {
return nil
}
self = result
}
public var rawValue: String {
guard let data = try? JSONEncoder().encode(self), // data is Data type
let result = String(data: data, encoding: .utf8) // coerce NSData to String
else {
return "{}" // empty Dictionary represented as String
}
return result
}
}
public enum Language: String, Codable, {
case en = "en"
case fr = "fr"
case ja = "ja"
case ko = "ko"
case hr = "hr"
case de = "de"
}
This all works fine in my app, however trying to run any tests, the build fails with the following:
Conflicting conformance of 'Dictionary<Key, Value>' to protocol 'RawRepresentable'; there cannot be more than one conformance, even with different conditional bounds
But then when I comment out my RawRepresentable implementation, I get the following error when attempting to run tests:
Value of type 'ScriptPickers' (aka 'Dictionary<Language, Bool>') has no member 'rawValue'
I hope Joseph Heller is out there somewhere chuckling at my predicament
any/all ideas greatly appreciated
I have a class that I want to custom encode into JSON:
class Declination: Decodable, Encodable {
var asString: String
var asDouble: Double
init(_ asString: String) {
self.asString = asString
self.asDouble = raToDouble(asString)
}
required init(from decoder: Decoder) throws {
let value = try decoder.singleValueContainer()
self.asString = try value.decode(String.self)
self.asDouble = declinationToDouble(asString)
}
}
As you can see, I calculate the double form of the declination when I decode a JSON file containing the data. What I want to do now is ENCODE the class back out as a single string.
Currently the standard JSON encode in Swift produces the following:
"declination":{"asDouble":18.26388888888889,"asString":"+18:15:50.00"}
what I want to produce is:
declination:"+18:15:50.00"
How can I easily do that? I've read up about custom encoders and such, and I get confused about the containers and what keys are being used. I think there might be a simple answer where I could just code:
extension Coordinate: Encodable {
func encode(to encoder: Encoder) throws {
return encoder.encode(self.asString)
}
}
But experienced Swift developers will immediately see that won't work. Should I do JSONSerialization instead? Can I just write a toString() extension and have JSON pick that up?
Any help would be appreciated.
Thanks,
Robert
Topic:
Programming Languages
SubTopic:
Swift
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!
Hey team I'm facing an issue where startDate is 1 January 2025 and endDate is 31 March 2025 between this 2 dates is 90 days, but on my code is being taken as 89 days
I've seen the math of the code excludes the first partial day (from midnight to 06:00) on 2025-01-01, which results in 89 full days instead of 90 days.
startDate: 2025-01-01 06:00:00 +0000
endDate: 2025-03-31 06:00:00 +0000
this is my function
func daysBetweenDates() -> Int? {
guard let selectedStartDate = selectedStartDate?.date else { return nil }
guard let selectedEndDate = selectedEndDate?.date else { return 0 }
let calendar = Calendar.current
let dateComponents = calendar.dateComponents([.day], from: selectedStartDate, to: selectedEndDate)
return dateComponents.day
}
what I've tried is reset the hours to 0 so it can take the full day and return 90 days
like this
func daysBetweenDates() -> Int? {
guard let selectedStartDate = selectedStartDate?.date else { return nil }
guard let selectedEndDate = selectedEndDate?.date else { return 0 }
var calendar = Calendar(identifier: .gregorian)
calendar.timeZone = TimeZone(secondsFromGMT: 0) ?? .current
let cleanMidNightStartDate = calendar.startOfDay(for: selectedStartDate)
let cleanMidNightEndDate = calendar.startOfDay(for: selectedEndDate.addingTimeInterval(24 * 60 * 60))
let dateComponents = calendar.dateComponents([.day], from: cleanMidNightStartDate, to: cleanMidNightEndDate)
let daysCount = dateComponents.day ?? 0
return daysCount
}
this worked for that date specifically but when I tried to change the date for example
startDate: 18 December 2024.
endDate: 18 March 2025.
between those dates we have 90 days but this function now reads 91.
what I'm looking is a cleaver solution for this problem so I can have the best posible quality code, thanks in advance!
Topic:
Programming Languages
SubTopic:
Swift
I just added a .systemLarge widget to my app, but I can't get Links to work. I want the user to be able to tap one of the four rows in my widget - like the EmojiRangers example - but I can't get it to work.
I watched a Developer video from WWDC20: https://developer.apple.com/videos/play/wwdc2020/10036?time=223
The guy, Izzy, 'simply' embeds an HStack in a Link, and hey presto! It all works. But that doesn't happen for me. There's clearly some code in the background that runs.
I already have .widgetURL working for .systemSmall and .systemMedium widgets, and I don't need to use Links on those two types. Those work by sending a URL to .onOpenURL { incomingURL in ... All good there, no issues.
I've wrapped each row in the large widget in a Link with the URL of something like myappurlscheme://widgetTapped/widgetId (it's the same url as that used in the small and medium widgets). I build & run. I tap a row. It doesn't act as though a row is tappable (it doesn't go slightly transparent), and just opens the app without hitting .onOpenURL or anything else. Nothing in my scene delegate is triggered. Is there a specific delegate method that gets called? Do I need to set up some awful intents?
I'm not using any sort of NavigationStack here; that model doesn't fit my app.
Any ideas? Thanks.
Is it ok for an Actor type to have a Publisher as a property to let others observe changes over time? Or use the @Published property wrapper to achieve this?
actor MyActor {
var publisher = PassthroughSubject<Int, Never>()
var data: Int {
didSet {
publisher.send(data)
}
}
...
}
// Usage
var tasks = Set<AnyCancellable>()
let actor = MyActor()
Task {
let publisher = await actor.publisher
publisher.sink { print($0) }.store(in: &tasks)
}
This seems like this should be acceptable. I would expect a Publisher to be thread safe, and as long as the Output is a value type things should be fine.
I have been getting random EXC_BAD_ACCESS errors when using this approach. But turning on the address sanitizer causes these crashes to go away. I know that isn't very specific but I wanted to start by seeing if this type of pattern is ok to do.
I have configured DateFormatter in the following way:
let df = DateFormatter()
df.dateFormat = "yyyy-MM-dd'T'HH:mm:ss'Z'"
df.locale = .init(identifier: "en")
df.timeZone = .init(secondsFromGMT: 0)
in some user devices instead of ISO8601 style it returns date like 09/25/2024 12:00:34
Tried to change date format from settings, changed calendar and I think that checked everything that can cause the problem, but nothing helped to reproduce this issue, but actually this issue exists and consumers complain about not working date picker.
Is there any information what can cause such problem? May be there is some bug in iOS itself?
Is anyone have this problem on xcode 26 ?
Undefined symbol: _swift_FORCE_LOAD$_swiftCompatibility50
Undefined symbol: _swift_FORCE_LOAD$_swiftCompatibility51
Undefined symbol: _swift_FORCE_LOAD$_swiftCompatibility56
Undefined symbol: _swift_FORCE_LOAD$_swiftCompatibilityConcurrency
Undefined symbol: _swift_FORCE_LOAD$_swiftCompatibilityDynamicReplacements
I am a Chinese student beginner ,do you have any advice for me to learn swift?I don't know how to start it.Please!🙏
Topic:
Programming Languages
SubTopic:
Swift
Module compiled with Swift 6.0.3 cannot be imported by the Swift 6.1 compiler: /private/var/tmp/_bazel_xx/8b7c61ad484d9da1bf94a11f12ae6ffd/rules_xcodeproj.noindex/build_output_base/execroot/main/CustomModules/BIYThred/CocoaLumberjack/framework/CocoaLumberjack.framework/Modules/CocoaLumberjack.swiftmodule/arm64-apple-ios.swiftmodule
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