I've been working on an iOS app with UIDocuments. They were saving fine. Now all of a sudden, after unrelated changes, nothing will save. Here is the error printed in Xcode console: *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSURL URLByAppendingPathExtension:]: component, components, or pathExtension cannot be nil.' log.debug("save to:\(self.document.fileURL)") document.save(to: document.fileURL, for: .forOverwriting) { success in ... } The log message there prints a valid URL.

I want to show a custom confirmation dialog on my iPad. It pops up looking utterly ridiculous because the size is way bigger than it needs - inches of padding on all sides. Is there still no way to control a sheet size on iPad? Example code: struct ContentView: View {     @State var showSheet = false     var body: some View {         Button("Show sheet") {             showSheet = true         }.sheet(isPresented: $showSheet) {             VStack(spacing: 0) {                 Text("Title")                 Divider()                 Text("Line 1")                 Text("Line 2. Blah blah blah blah.")                 Divider()                 HStack {                     Button("Cancel") { showSheet = false }                     Divider()                     Button("OK") { showSheet = false }                 }.fixedSize(horizontal: false, vertical: true)             }             .frame(minWidth: 0, minHeight: 0)             .fixedSize()         }     } } The result:

I think they are, but I got myself into a situation with this error: // Inside a SwiftUI View struct... let cancelled: @MainActor () -> Void var body: some View { ... Button(action: self.cancelled) { Text("Cancel") } // Error here The compiler reports: Converting function value of type '@MainActor () -> Void' to '() -> Void' loses global actor 'MainActor' I originally put that attribute on the cancelled property, because in the passed-in closure, I was doing something that gave me an error about how I had to be on the MainActor.

I can't find any documentation on this. I've tried adding png files to my project and adding them with the "+" button here, but Xcode just ignores me. No error message. Is it looking for a specific file format? This is Xcode 13.

Here's the entire app below. On iOS 15, it pops up blank. If you dismiss it and click "Share" again, then it looks right. Is this a bug, or is the code wrong? struct ContentView: View {     @State private var showShare = false     @State private var shareItems: [Any] = []     var body: some View {         VStack {             Text("Test ActivityViewController")             Button("Share") {                 share()             }.sheet(isPresented: $showShare) {                 print("dismissed")             } content: {                 ActivityViewController(activityItems: shareItems)             }         }     }     func share() {         shareItems = ["test"]         showShare = true     } } struct ActivityViewController: UIViewControllerRepresentable {     let activityItems: [Any]     func makeUIViewController(context: Context) -> UIActivityViewController {         let c = UIActivityViewController(activityItems: activityItems, applicationActivities: nil)         return c     }     func updateUIViewController(_ uiViewController: UIActivityViewController, context: Context) {} }

You used to be able to put two wheel Pickers side-by-side in an HStack, if you used .frame(...) to set the width, along with .clipped(). Example code from previous question here: https://developer.apple.com/forums/thread/127028 HStack(spacing: 0) { Picker(selection: $choice1, label: Text("C1")) { ForEach(0..<10) { n in Text("\(n) a").tag(n) } } .pickerStyle(.wheel) .frame(minWidth: 0) .clipped() // repeat with second Picker } This is not working for me now in iOS 15. The views still appear side by side, but the touch area seems to overlap. When you try to adjust the first wheel, it spins the second one. I can move the first wheel, if I touch way over to the leading side of the screen. (I had to add the explicit Picker style. It seems like defaulting to .menu also started in iOS 15. ?)

Simple code like this gives an error. struct MyView: View {     @State private var test: Bool = false     var body: some View {           Text("Hello. \(test)") The error: Instance method 'appendInterpolation(_:formatter:)' requires that 'Bool' inherit from 'NSObject' What is going on?

These are properties of Product. Both are type VerificationResult<Transaction>? and they seem very similar. What are some example situations where they would be different? It would be nice if the documentation discussed this.

After updating to 12.5, I now get an error trying to run my unit tests. This is for a macOS app. dyld: warning: could not load inserted library '/[...]/DerivedData/[...]/Contents/Frameworks/libXCTestBundleInject.dylib' into hardened process because no suitable image found.  Did find: /[...]/libXCTestBundleInject.dylib: code signature in (/[...]/libXCTestBundleInject.dylib) not valid for use in process using Library Validation: mapped file has no Team ID and is not a platform binary (signed with custom identity or adhoc?) Anyone else face and fix this, or understand what it is? I changed the "Signing Certificate" in my test target to "Sign to Run Locally" (from "Development") to see if that would help. It didn't fix it.

Is there a way to quickly confirm a "fix-it" popup using only the keyobard? The "Fix Next Issue" and "Fix Previous Issue" commands just show the popup. I still have to manually press the "Fix" button. Return key simply dismisses the popup. Clicking that tiny button 1000's of times is annoying. Xcode 12.4. In IntelliJ I can fly through these with a nice keyboard shortcut. I'm looking for a similar thing in Xcode.

Hi, If I change the AppIcon in Xcode's Assets.xcassets, and rerun my app, the image used in the dock and app switcher does not update. If I "Clean Build Folder", and re-run, then it updates. This is annoying when I keep tweaking the colors in the icon and want to see how they look. A full rebuild takes a while, because I have a few Swift Package dependencies. Anyone know a trick to get the AppIcon to stop caching (or whatever it's doing)? I tried killall Dock and killall Finder, but that didn't help. (macOS 11.2.3) Rob

My app crashes and Xcode shows no stack trace. It just pops up some line of assembly language in __pthread_kill, and shows this in the console: [error] precondition failure: invalid value type for attribute: 230424 (saw PreferenceKeys, expected ViewList) AttributeGraph precondition failure: invalid value type for attribute: 230424 (saw PreferenceKeys, expected ViewList). Seems like a bug in SwiftUI. Any ideas? This is on macOS 11.

This appears to severely limit the usefulness of hierarchical lists in SwiftUI. I want to use the new hierarchical list/outline to display a filesystem tree. For data to pass to OutlineGroup, I created a class named FileSystemNode, and gave it a computed children property. When the getter is first called, it will read its directory contents to return a list (if it is a directory). Problem is, when the OutlineGroup is first displayed, even though it is collapsed on-screen to a single node, it calls children and recurses over the entire filesystem. Is there a way to stop this? If not, I hope it gets fixed before release. (This is on macOS Big Sur beta)

Hi, I want something like sandbox-exec, so I can run things that I don't trust, and restrict their ability to read or write files to only certain locations. Like most software devs I have to download and run lots of code from the internet and the danger of this really annoys me. Unfortunately sandbox-exec is marked as deprecated and the APIs in sandbox.h say "No longer supported". I notice there is some new stuff in the Apple docs about "hypervisors" and "virtualization". https://developer.apple.com/documentation/hypervisor https://developer.apple.com/documentation/virtualization Would these APIs allow me to start and control a virtual copy of my macOS, to serve like a sandbox? Are there other solutions that people use? As an example, say that I need to download and run a copy of memcached. It's a typical open source project – you unpack a source tgz, then run configure; make and get a binary. Now I want to run that without worrying that some hacker injected a piece of evil code to copy my files and send them somewhere. So I want to say "run this binary, while disallowing file reads and writes, except for directories X,Y,Z, and disallowing network connections, except for listening on port 1234."

Does anyone use the new hierarchical data List (ie, OutlineGroup) with a model where the tree data changes? I'm on Big Sur beta. I have code like this: List([treeRoot], children: \.children) { item in ... Say the treeRoot (observed object) gets a new child. The view tries to re-render and fails: 2020-09-21 ... [General] NSOutlineView error inserting child indexes <_NSCachedIndexSet: 0x600000760000>[number of indexes: 1 (in 1 ranges), indexes: (3)] in parent 0x0 (which has 1 children).