stephen-hawley
commented
1 month ago One thing to keep in mind is that swift strings are...interesting.
If you're running on a 64 bit platform, the underlying representation of the string will vary depending on how the string is being used. There is a discriminator which determines the underlying string representation which could also be an inline value in the 64 bits (these are small strings). In the Apple repository you can see what they're doing. It's very complicated. Simply put, Swift String is not NSString and your class is not returning NSString.
What you can try is to rewrite your methods to work in NSString instead of String:
@objc public func returnString(input:NSString)->NSString{
return ("You gave me " + (input as String)) as NSString
// or if you want it to be easier to read:
// return "You gave me \(input)" as NSString
}
kwende
Steps to Reproduce
Please note that example code is available here: https://github.com/kwende/iosMauiBindingLibrary/tree/main. There are two branches: Crashes and Works that show the issue I'm reporting.
Expected Behavior
I would expect to be able to return a String from my Swift wrapper classes. It's not clear to me what the issue is. In other tests I've not gotten the linker error, but instead an SIGSEGV when attempting to return a string.
Actual Behavior
I get a crash instead of the string being returned, or the app fully loading. When the app doesn't load properly (which the github example provided shows, you get the following output (note the symbol not found):
In another app of ours we don't get the missing symbol error, instead we get a crash :
My believe is these are two different results of the same problem: somehow strings aren't able to be returned correctly from Swift functions.
Environment
Version information
``` Visual Studio Professional 2022 for Mac Version 17.6.13 (build 424) Installation UUID: fc7f15f4-1d85-406d-9a6b-e1582c4f2fff Runtime .NET 7.0.3 (64-bit) Architecture: Arm64 Microsoft.macOS.Sdk 13.1.1007; git-rev-head:8afca776a0a96613dfb7200e0917bb57f9ed5583; git-branch:release/7.0.1xx-xcode14.2 Roslyn (Language Service) 4.6.0-3.23180.6+99e956e42697a6dd886d1e12478ea2b27cceacfa NuGet Version: 6.4.0.117 .NET SDK (Arm64) SDK: /usr/local/share/dotnet/sdk/8.0.204/Sdks SDK Versions: 8.0.204 7.0.317 7.0.316 6.0.424 6.0.422 6.0.100 MSBuild SDKs: /Applications/Visual Studio.app/Contents/MonoBundle/MSBuild/Current/bin/Sdks .NET Runtime (Arm64) Runtime: /usr/local/share/dotnet/dotnet Runtime Versions: 8.0.4 7.0.20 7.0.19 6.0.32 6.0.30 6.0.0 Xamarin.Profiler Version: 1.8.0.49 Location: /Applications/Xamarin Profiler.app/Contents/MacOS/Xamarin Profiler Updater Version: 11 Xamarin.Android Version: 13.2.2.0 (Visual Studio Professional) Commit: xamarin-android/d17-5/45b0e14 Android SDK: /Users/ocuvera/Library/Developer/Xamarin/android-sdk-macosx Supported Android versions: 6.0 (API level 23) 12.0 (API level 31) 11.0 (API level 30) 10.0 (API level 29) 13.0 (API level 33) SDK Command-line Tools Version: 7.0 SDK Platform Tools Version: 33.0.3 SDK Build Tools Version: 32.0.0 Build Information: Mono: d9a6e87 Java.Interop: xamarin/java.interop/d17-5@149d70fe SQLite: xamarin/sqlite/3.40.1@68c69d8 Xamarin.Android Tools: xamarin/xamarin-android-tools/d17-5@ca1552d Microsoft Build of OpenJDK Java SDK: /Library/Java/JavaVirtualMachines/microsoft-11.jdk 11.0.16.1 Android Designer EPL code available here: https://github.com/xamarin/AndroidDesigner.EPL Eclipse Temurin JDK Java SDK: /Library/Java/JavaVirtualMachines/temurin-8.jdk 1.8.0.302 Android Designer EPL code available here: https://github.com/xamarin/AndroidDesigner.EPL Android SDK Manager Version: 17.6.0.50 Hash: a715dca Branch: HEAD Build date: 2024-07-09 00:12:30 UTC Android Device Manager Version: 0.0.0.1309 Hash: 06e3e77 Branch: HEAD Build date: 2024-07-09 00:12:30 UTC Apple Developer Tools Xcode: 15.2 22503 Build: 15C500b Xamarin.Mac Not Installed Xamarin.iOS Version: 16.4.0.23 Visual Studio Professional Hash: 9defd91b3 Branch: xcode14.3 Build date: 2023-10-23 16:15:00-0400 Xamarin Designer Version: 17.6.3.9 Hash: 2648399ae8 Branch: remotes/origin/d17-6 Build date: 2024-07-09 00:12:23 UTC Build Information Release ID: 1706130424 [build-log.txt](https://github.com/user-attachments/files/16289551/build-log.txt) Git revision: acd381f8e8bd7deca64bdf93287dc0849a0e73f5 Build date: 2024-07-09 00:10:15+00 Build branch: release-17.6 Build lane: release-17.6 Operating System Mac OS X 14.5.0 Darwin 23.5.0 Darwin Kernel Version 23.5.0 Wed May 1 20:16:51 PDT 2024 root:xnu-10063.121.3~5/RELEASE_ARM64_T8103 arm64 ```Build Logs
build-log.txt
Example Project (If Possible)
https://github.com/kwende/iosMauiBindingLibrary