We're excited to announce our first preview release for .NET 9!

Note: these are the base SDKs that add support for the platforms in question. For MAUI (which is built on top of our SDKs), visit: https://learn.microsoft.com/dotnet/maui/.

This release consists of the following versions:

• iOS: 17.2.9088-net9-p1
• tvOS: 17.2.9088-net9-p1
• Mac Catalyst: 17.2.9088-net9-p1
• macOS: 14.2.9088-net9-p1

Full release notes: .NET 9 release notes
Known issues: Known issues in .NET 9

What's Changed

API improvements / fixes / additions

• [AppKit/UIKit] Adjust a few availability attributes in NS[Mutable]ParagraphStyle. Fixes #19209. by @rolfbjarne in #19211
• [AppKit] Add support for Xcode 15. by @mandel-macaque in #19119
• [AppKit] Fix binding for NSFontDescriptor.Create. Fixes #19659. by @rolfbjarne in #19663
• [AppKit] Implement the NSUserInterfaceItemSearching protocol. Fixes #19649. by @rolfbjarne in #19662
• [AppKit] Make NSGraphics.NSBestDepth P/Invoke blittable. by @rolfbjarne in #19614
• [AppKit] Remove [NSImage imageWithSymbolName:bundle:variableValue:] from Mac Catalyst. by @rolfbjarne in #19320
• [AppKit] Update the NSBezelStyle enum according to latest headers. Fixes #19555. by @rolfbjarne in #19556
• [AudioToolbox] Make P/Invokes in AudioFileStream.cs have blittable signatures. by @rolfbjarne in #19835
• [AudioToolbox] Make P/Invokes in AudioServices.cs have blittable signatures. by @rolfbjarne in #19841
• [AudioToolbox] Make P/Invokes in MusicPlayer.cs have blittable signatures. by @rolfbjarne in #19694
• [AudioToolbox] Make P/Invokes in MusicTrack.cs have blittable signatures. by @rolfbjarne in #19678
• [AudioToolbox] Make P/Invokes in SystemSound.cs have blittable signatures. by @rolfbjarne in #19677
• [AutomaticAssessmentConfiguration] Add missing constructors to AEAssessmentApplication. Fixes #19133. by @rolfbjarne in #19180
• [CoreBluetooth] Fix a typo in CBPeripheralDelegate.DiscoveredService for XAMCORE_5_0. by @rolfbjarne in #19582
• [CoreMidi] Add CoreMidi enums to Watch so that we can have them for avfoundation. by @mandel-macaque in #19580
• [CoreMidi] Add support for tvOS. by @mandel-macaque in #19529
• [CoreMidi] Make P/Invokes have blittable signatures. by @rolfbjarne in #19706
• [CoreMidi] Make P/Invokes have blittable signatures. by @rolfbjarne in #19724
• [CoreMidi] Obsolete the MidiPacket.Bytes property. by @rolfbjarne in #19705
• [CoreText] Fix a few nullability issues in CTFontDescriptor. by @rolfbjarne in #19439
• [CoreText] Implement CTFontDescriptor.MatchFontDescriptors. Fixes #19397. by @rolfbjarne in #19399
• [Foundation] Add support for Xcode 15 beta 7. by @mandel-macaque in #19007
• [Foundation] Bind a few missing notifications. Fixes #19837. by @rolfbjarne in #19846
• [Foundation] Create a strong dictionary for NSAttributedStringDocumentReadingOptionKey. by @rolfbjarne in #19667
• [Foundation] Fix a few issues with NSUrlConnection.SendSynchronousRequest. by @rolfbjarne in #19458
• [Foundation] Improve visibility of NSObject members in intellisense by @haritha-mohan in #19106
• [Foundation] Make P/Invokes in NSDecimal.cs have blittable signatures. by @rolfbjarne in #19702
• [Foundation] NSArray.FromNSObjects will never return null objects. Fixes #19622. by @rolfbjarne in #19627
• [GameKit] Add support for Xcode 15 by @haritha-mohan in #19285
• [ImageIO] Make P/Invokes have blittable signatures. by @rolfbjarne in #19701
• [InputMethodKit] Remove existing code for InputMethodKit. by @rolfbjarne in #19462
• [LocalAuthentication] Make path have the correct case by @rolfbjarne in #19465
• [Metal] Add support for Xcode15. by @mandel-macaque in #19379
• [MetalFX] Add the framework (which was added in Xcode 14) and add xcode 15 support. by @mandel-macaque in #19107
• [MetalKit] Add support for Xcode 15. by @mandel-macaque in #19274
• [ModelIO] Include MDLMaterial.cs in the build. by @rolfbjarne in #19464
• [NerabyInteraction] Add support for xcode 15. by @mandel-macaque in #19273
• [Network] Add support for Xcode 15. by @mandel-macaque in #19418
• [ObjCRuntime] Cache a few expensive and frequent operations in Class. Fixes #19079. by @rolfbjarne in #19086
• [ObjCRuntime] Throw a more descriptive InvalidCastException when failing to create an instance of the appropriate type in Runtime.CreateNSObject. by @rolfbjarne in #19629
• [PassKit] Add support Xcode15 Beta 7 by @tj-devel709 in #19139
• [PassKit] Fix the intro tests for PassKit on macOS. by @mandel-macaque in #19760
• [Speech] Fix wrong added API in macOS. by @mandel-macaque in #19759
• [Storekit] Add support for xcode 15. by @mandel-macaque in #19309
• [UIKit] Add missing attrs for catalyst. by @mandel-macaque in #19355
• [UIKit] Add support for Xcode 15. by @mandel-macaque in #19120
• [UIKit] Adjust availability attributes for UIButtonConfiguration.[Sub]TitleLineBreakMode. Fixes ##19377. by @rolfbjarne in #19384
• [UIKit] Fix a few nullability issues by @rolfbjarne in #19688
• [UIKit] Fix broken UITrait bindings. Fixes #19410. by @rolfbjarne in #19411
• [UIKit] Make P/Invokes have blittable signatures. by @rolfbjarne in #19725
• [UIKit] Make P/Invokes related to UIAccessibility have blittable signatures. by @rolfbjarne in #19698
• [UIKit] Store the delegate in a local variable in the UIContextMenuInteraction. by @rolfbjarne in #19386
• [Vision] Add support for Xcode 15 by @haritha-mohan in #19099
• [Vision] Make P/Invokes have blittable signatures. by @rolfbjarne in #19703
• [Vision] Update Xcode 15 support by @haritha-mohan in #19412
• [WebKit] Add missing notification attrs. by @mandel-macaque in #19275
• [WebKit] Add support for Xcode 15 by @haritha-mohan in #19237
• Fix sending MidiPacket when MidiPacket has been created using a point… by @jamesdlow in #18981

Misc bug fixes / improvements

• [bgen] Adjust logic to handle protocol-backed events. by @rolfbjarne in #19689
• [bgen] Fix assembly comparison. Fixes #19612. by @rolfbjarne in #19619
• [bgen] Fix generated code to be nullability correct. by @rolfbjarne in #19655
• [bgen] Fix logic to handle protocol-backed events. by @rolfbjarne in #19707
• [Generator] == on a type those a reference equals check. by @mandel-macaque in #19756
• [Generator] Add BindingTouchConfig to BindingTouch by @dustin-wojciechowski in #19485
• [Generator] Allow to have a way to attach to the generator. by @mandel-macaque in #19565
• [Generator] Clean the AttributeManager from deps and fix a bug in the errors. by @mandel-macaque in #19532
• [Generator] Do not couple BindingTouch to the TypeCache. by @mandel-macaque in #19426
• [Generator] Group all those classes that act as a Cache. by @mandel-macaque in #19480
• [Generator] Implement TypeCache. by @dustin-wojciechowski in #19398
• [Generator] Move the most of the path logic out of BT. by @mandel-macaque in #19429
• [Generator] Move the NSValue create map to the TypeCache. by @mandel-macaque in #19495
• [Generator] Move Type-related methods into Type Manager by @dustin-wojciechowski in #19380
• [Generator] New LibraryManager for BindingTouch by @dustin-wojciechowski in #19479
• [Generator] Provide a way to get all the types from the assembly. by @mandel-macaque in #19481
• [Generator] Refactor Format Type methods into TypeManager class by @dustin-wojciechowski in #19331
• [Generator] Refactor ReferenceFixer and SearchPathsAssemblyResolver by @dustin-wojciechowski in #19428
• [Generator] Remove a dict to which we only write and never read. by @mandel-macaque in #19483
• [Generator] Remove dead code. by @mandel-macaque in #19496
• [Generator] Remove method that adds no value. by @mandel-macaque in #19482
• [Generator] Remove properties that are used very few times. by @mandel-macaque in #19531
• [Generator] Remove the BT reference from the NSManager. by @mandel-macaque in #19427
• [Generator] The Nomenclator does know how to get the name of a type. by @mandel-macaque in #19530
• [Generator] Try to make the project a little more manageable. by @mandel-macaque in #19460
• [Generator] TryLoadApi method by @dustin-wojciechowski in #19470
• [docs] Document NativeAOT support. Fixes #18585. by @rolfbjarne in #19362
• [docs] Improve a few things in the managed static registrar doc. by @rolfbjarne in #19368
• [dotnet-linker] Remove code/file we don't need by @rolfbjarne in #19447
• [dotnet/msbuild] Create directory in the ILStrip task instead of using MSBuild logic. by @rolfbjarne in #19181
• [dotnet] Call the _CreateAssetPackManifest target during the build. Fixes #19669. by @rolfbjarne in #19681
• [dotnet] Complete support for universal builds when using NativeAOT. by @rolfbjarne in #19183
• [dotnet] Compute the path to the Xamarin SDK root as a relative path to .NET's root directory. by @rolfbjarne in #19404
• [dotnet] Fix 'make install-system' to use 'dotnet workload install' instead of packages. by @rolfbjarne in #19755
• [dotnet] Fix detecting if the interpreter is enabled. by @rolfbjarne in #19812
• [dotnet] Generate WorkloadManifest.targets for each platform using a script. by @rolfbjarne in #19421
• [dotnet] Remove support for MtouchArch and XamMacArch. by @rolfbjarne in #19319
• [dotnet] Stop using a separate default platform version. by @rolfbjarne in #19754
• [dotnet] Store the .NET version we target in a generated props file. by @rolfbjarne in #19416
• [dotnet] Test integration by @stephen-hawley in #18543
• [dotnet] Use the correct variable to define the verbosity for 'dotnet build' by @rolfbjarne in #19676
• [hotrestart] Ensure we set the correct value for the "IsHotRestartBuild" property by @mauroa in #19103
• [msbuild/dotnet] Add support for app extensions which are xpc services. by @rolfbjarne in #18295
• [msbuild] Copy files to be signed into the correct directory for Hot Restart. Fixes #19278. by @rolfbjarne in #19302
• [msbuild] Copy the entire frameworks to the Mac when building remotely in the ResolveNativeReferences task. Fixes #19173. by @rolfbjarne in #19227
• [msbuild] Deduplicate code to create lists of TaskItems for each file in a directory recursively. by @rolfbjarne in #19382
• [msbuild] Detect any dylibs in NativeReferences. Fixes #19520. by @rolfbjarne in #19560
• [msbuild] Don't add frameworks with static libraries to Hot Restart apps. by @rolfbjarne in #19300
• [msbuild] Don't try to read a file that might not exist in the XamarinBuildTask task. by @rolfbjarne in #19327
• [msbuild] Enable nullability in all project files + disable nullability in each file. by @rolfbjarne in #19452
• [msbuild] Enable the _ExpandNativeReferences target for Hot Restart. by @rolfbjarne in #19299
• [msbuild] Fix check for Link metadata by checking for both null and empty string. Fixes #12783. by @rolfbjarne in #18487
• [msbuild] Fix parsing single-char mtouch extra args of the form '-vvvv'. by @rolfbjarne in #19318
• [msbuild] Fix resolving static libraries inside an XCFramework in a NuGet. by @rolfbjarne in #19502
• [msbuild] Handle backslash characters better on Windows in the ParseBundlerArguments task. by @rolfbjarne in #19719
• [msbuild] Improve makefile dependency in msbuild. by @rolfbjarne in #19640
• [msbuild] Look for and copy binding resource packages to the remote Mac in the ResolveNativeReferences task. Fixes #19229. by @rolfbjarne in #19325
• [msbuild] Merge the ACTool[TaskBase] classes. by @rolfbjarne in #19474
• [msbuild] Merge the AOTCompile[TaskBase] classes. by @rolfbjarne in #19475
• [msbuild] Merge the ArTool[TaskBase] classes. by @rolfbjarne in #19477
• [msbuild] Merge the Codesign[TaskBase] classes. by @rolfbjarne in #19498
• [msbuild] Merge the CollectBundleResources[TaskBase] classes. by @rolfbjarne in #19499
• [msbuild] Merge the CompileAppManifest[TaskBase] classes. by @rolfbjarne in #19500
• [msbuild] Merge the CompileEntitlements[TaskBase] classes. by @rolfbjarne in #19525
• [msbuild] Merge the CompileNativeCode[TaskBase] classes. by @rolfbjarne in #19527
• [msbuild] Merge the CompileProductDefinition[TaskBase] classes. by @rolfbjarne in #19548
• [msbuild] Merge the CompileSceneKitAssets[TaskBase] classes. by @rolfbjarne in #19573
• [msbuild] Merge the ComputeBundleLocation[TaskBase] classes. by @rolfbjarne in #19551
• [msbuild] Merge the ComputeBundleResourceOutputPaths[TaskBase] classes. by @rolfbjarne in #19552
• [msbuild] Merge the ComputeCodesignItems[TaskBase] classes. by @rolfbjarne in #19575
• [msbuild] Merge the ComputeRemoteGeneratorProperties[TaskBase] classes. by @rolfbjarne in #19576
• [msbuild] Merge the CoreMLCompiler[TaskBase] classes. by @rolfbjarne in #19588
• [msbuild] Merge the CreateAssetPackManifest[TaskBase] classes. by @rolfbjarne in #19589
• [msbuild] Merge the CreateDebugConfiguration[TaskBase] classes. by @rolfbjarne in #19615
• [msbuild] Merge the CreateDebugSettings[TaskBase] classes. by @rolfbjarne in #19630
• [msbuild] Merge the CreateEmbeddedResources[TaskBase] classes. by @rolfbjarne in #19631
• [msbuild] Merge the CreateInstallerPackage[TaskBase] classes. by @rolfbjarne in #19641
• [msbuild] Merge the CreatePkgInfo[TaskBase] classes. by @rolfbjarne in #19642
• [msbuild] Merge the DetectDebugNetworkConfiguration[TaskBase] classes. by @rolfbjarne in #19656
• [msbuild] Merge the DetectSigningIdentity[TaskBase] classes. by @rolfbjarne in #19660
• [msbuild] Merge the Ditto[TaskBase] classes. by @rolfbjarne in #19661
• [msbuild] Merge the DSymUtil[TaskBase] classes. by @rolfbjarne in #19643
• [msbuild] Merge the EmbedProvisionProfile[TaskBase] classes. by @rolfbjarne in #19672
• [msbuild] Merge the FilterStaticFrameworks[TaskBase] classes. by @rolfbjarne in #19673
• [msbuild] Merge the FindItemWithLogicalName[TaskBase] classes. by @rolfbjarne in #19674
• [msbuild] Merge the GenerateBundleName[TaskBase] classes. by @rolfbjarne in #19683
• [msbuild] Merge the GetDirectories[TaskBase] classes. by @rolfbjarne in #19685
• [msbuild] Merge the GetFileSystemEntries[TaskBase] classes. by @rolfbjarne in #19686
• [msbuild] Merge the GetFullPath[TaskBase] classes. by @rolfbjarne in #19718
• [msbuild] Merge the GetNativeExecutableName[TaskBase] classes. by @rolfbjarne in #19720
• [msbuild] Merge the GetPropertyListValue[TaskBase] classes. by @rolfbjarne in #19721
• [msbuild] Merge the IBTool[TaskBase] classes. by @rolfbjarne in #19739
• [msbuild] Merge the InstallNameTool[TaskBase] classes. by @rolfbjarne in #19740
• [msbuild] Merge the LinkNativeCode[TaskBase] classes. by @rolfbjarne in #19741
• [msbuild] Merge the MergeAppBundles[TaskBase] classes. by @rolfbjarne in #19751
• [msbuild] Merge the Metal[TaskBase] classes. by @rolfbjarne in #19753
• [msbuild] Merge the MetalLib[TaskBase] classes. by @rolfbjarne in #19752
• [msbuild] Merge the OptimizeImage[TaskBase] classes. by @rolfbjarne in #19774
• [msbuild] Merge the OptimizePropertyList[TaskBase] classes. by @rolfbjarne in #19775
• [msbuild] Merge the PackLibraryResources[TaskBase] classes. by @rolfbjarne in #19783
• [msbuild] Merge the ParseBundlerArguments[TaskBase] classes. by @rolfbjarne in #19787
• [msbuild] Merge the ParseDeviceSpecificBuildInformation[TaskBase] classes. by @rolfbjarne in #19789
• [msbuild] Merge the PrepareNativeReferences[TaskBase] classes. by @rolfbjarne in #19792
• [msbuild] Merge the PrepareResourceRules[TaskBase] classes. by @rolfbjarne in #19825
• [msbuild] Merge the PropertyListEditor[TaskBase] classes. by @rolfbjarne in #19827
• [msbuild] Merge the ReadAppManifest[TaskBase] classes. by @rolfbjarne in #19829
• [msbuild] Move shared/duplicated code into base XamarinBuildTask class from the FindILLink/FindAotCompiler tasks. by @rolfbjarne in #19360
• [msbuild] Parse --nowarn and --warnaserror from MtouchExtraArgs for .NET. by @rolfbjarne in #19540
• [msbuild] Remove the CodesignProvision property from the DetectSigningIdentity task. by @rolfbjarne in #19494
• [msbuild] Remove the CodesignVerify target. by @rolfbjarne in #19490
• [msbuild] Remove unused file. by @rolfbjarne in #19433
• [msbuild] Report a better error if a NativeResource doesn't exist on disk. by @rolfbjarne in #19199
• [msbuild] Subclass XamarinTask in numerous other tasks to reduce duplicated code. by @rolfbjarne in #19343
• [msbuild] Use a single generated versions file for all platforms. by @rolfbjarne in #19593
• [mtouch] Remove packages.config, doesn't seem to be used anymore. by @rolfbjarne in #19742
• [NativeAOT] Improve the transformation of [Preserve(AllMembers = true)] by @simonrozsival in #19516
• [net9.0] Drop support for .NET 7. by @rolfbjarne in #19887
• [runtime] Use objc_[retain|release|autorelease] instead of sending messages. by @rolfbjarne in #19415
• [src] Add a TransientCFString struct. by @rolfbjarne in #19763
• [src] Enable nullability by default and turn it off in files that haven't been audited/converted. by @rolfbjarne in #19680
• [src] Enable nullability in project files, and disable (for now) in files that haven't been processed yet. by @rolfbjarne in #19472
• [src] Fix the array itself and not the first array element. by @rolfbjarne in #19420
• [src] Interface members are public by default, so make these explicitly private. by @rolfbjarne in #19833
• [src] Rearrange code to avoid compiler warning. by @rolfbjarne in #19750
• [src] Remove the Protocolize attribute. by @rolfbjarne in #19684
• [src] Remove the UnifiedInternal attribute. by @rolfbjarne in #19687
• [src] Try to fix race condition with regards to restoring NuGet packages. by @rolfbjarne in #19467
• [src] Update dependencies of bgen.csproj to not use the dependencies of generator.csproj. by @rolfbjarne in #19572
• [src] Use proper return type for stret functions. by @rolfbjarne in #19682
• [Xcode 15.2] Bump to Xcode 15.2 by @dalexsoto in #19785
• Bump mlaunch to get device support for iOS 17. by @rolfbjarne in #19159
• Bump mlaunch to get fix for older devices. by @rolfbjarne in #19249
• Bump mlaunch to get resource fix. by @rolfbjarne in #19291
• Bump Touch.Unit and MonoTouch.Dialog. by @rolfbjarne in #19590
• Bump Xamarin.MacDev. by @rolfbjarne in #19734
• More methods extracted in BindingTouch [Generator] by @dustin-wojciechowski in #19635
• Revert "[MacCatalyst] Added Default Entitlements for MacCatalyst projects" by @dustin-wojciechowski in #19125
• Updating Xamarin.iOS.HotRestart.Client to 1.0.124 by @MSLukeWest in #19046

New Contributors

• @MSLukeWest made their first contribution in #19046
• @jamesdlow made their first contribution in #18981

Full Changelog: dotnet-8.0.1xx-xcode15.1-8004...dotnet-9.0.1xx-preview1-9088