We're excited to announce our fifth 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: 17.2.9639-net9-p5
• tvOS: 17.2.9639-net9-p5
• Mac Catalyst: 17.2.9639-net9-p5
• macOS: 14.2.9639-net9-p5

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

What's Changed

• [AudioUnit] Make P/Invokes in AudioUnit.cs have blittable signatures. by @rolfbjarne in #20620
• [AudioUnit] Make P/Invokes in AUGraph.cs have blittable signatures. by @rolfbjarne in #20636
• [AudioUnit] Remove unnecessary MarshalAs attributes from the AudioComponentDescription struct. by @rolfbjarne in #20565
• [bgen] Add support for binding constructors in protocols. Fixes #14039. by @rolfbjarne in #20583
• [bgen] Add support for marking API bindings as preview APIs using the Experimental attribute. by @rolfbjarne in #20591
• [bgen] Fix support for ErrorDomain enums in third-party bindings. by @rolfbjarne in #20499
• [bgen] Generate xml documentation for generated default constructors. by @rolfbjarne in #20525
• [bgen] Generate xml documentation for generated enums. by @rolfbjarne in #20511
• [bgen] Generate xml documentation for generated UIAppearance logic. by @rolfbjarne in #20502
• [bgen] Generate xml documentation for notifications. by @rolfbjarne in #20492
• [bgen] Generate xml documentation for the extension class we generate for protocols. by @rolfbjarne in #20564
• [Blocks] Remove a block callback validation that's apparently too eager. by @rolfbjarne in #20625
• [CoreMidi] Make MidiPacket.ByteArray and MidiPacket.BytePointer public by @Youssef1313 in #20540
• [CoreVideo] Make P/Invokes in CVBuffer and CVDisplayLink have blittable signatures. by @rolfbjarne in #20494
• [CoreVideo] Make P/Invokes in CVImageBuffer and CVMetalTexture[Cache] have blittable signatures. by @rolfbjarne in #20500
• [CoreVideo] Make P/Invokes in CVPixel related types have blittable signatures. by @rolfbjarne in #20510
• [Darwin] Make the 'kevent' P/Invoke have blittable signatures. by @rolfbjarne in #20467
• [docs] Review and update the 'Binding errors' document. by @rolfbjarne in #20481
• [dotnet] Make the VB templates compile use models instead of protocol interfaces. by @rolfbjarne in #20576
• [dotnet] Throw an exception if the developer tries to use server garbage collection. Fixes #16853. by @rolfbjarne in #20569
• [Foundation] Make P/Invokes have blittable signatures. by @rolfbjarne in #20539
• [Foundation] Use 'Foundation' as the namespace for NSUrlSessionHandler for all platforms. by @rolfbjarne in #20581
• [GameController] GCMouse doesn't conform to NSCoding/NSSecureCoding. by @rolfbjarne in #20641
• [GameController] Make P/Invokes have blittable signatures. by @rolfbjarne in #20528
• [GLKit] Make the GLKVertexAttributeParametersFromModelIO P/Invoke have a blittable signature. by @rolfbjarne in #20529
• [msbuild/dotnet] Automatically link with Swift's system libraries if a binding project has the IsSwift=true property. by @rolfbjarne in #20546
• [msbuild] Enable nullability in a few tasks. by @rolfbjarne in #20509
• [msbuild] Fix duplicated property declaration. by @rolfbjarne in #20549
• [msbuild] Fix issue referencing static libraries from compressed xcframeworks. by @rolfbjarne in #20585
• [msbuild] Improve errors in case native linking fails. by @rolfbjarne in #20462
• [msbuild] Improve the UnpackLibraryResources task a bit. by @rolfbjarne in #20004
• [msbuild] Make the IBTool task nullable. by @rolfbjarne in #20550
• [msbuild] Set the working directory before executing 'dotnet build' in the ComputeRemoteGeneratorProperties task. by @rolfbjarne in #20506
• [msbuild] Show a better error with invalid app bundles due to Resources subdirectory. Fixes #20135. by @rolfbjarne in #20593
• [msbuild] Version the Xamarin.Localization.MSBuild assembly. Fixes #20062. by @rolfbjarne in #20623
• [net9.0] Fix boolean condition to determine whether dynamic code is supported or not. Fixes #dotnet/runtime@101840. by @rolfbjarne in #20563
• [Network] Make P/Invokes in NWProtocol* have blittable signatures. by @rolfbjarne in #20638
• [ObjCRuntime] Make P/Invokes have blittable signatures. by @rolfbjarne in #20547
• [OpenGL/OpenGLES] Make P/Invokes have blittable signatures. by @rolfbjarne in #20512
• [PrintCore] Make P/Invokes have blittable signatures. by @rolfbjarne in #20542
• [runtime] Add support for additional type encodings. Fixes #18562. by @rolfbjarne in #20521
• [runtime] Fix memory leak with BlockLiteral descriptors. Fixes #20503. by @rolfbjarne in #20556
• [runtime] Throw exception for condition we don't handle in the dynamic registrar. by @rolfbjarne in #20568
• [SearchKit] Make P/Invokes have blittable signatures. by @rolfbjarne in #20493
• [Security] Make P/Invokes have in SslContext.cs blittable signatures. by @rolfbjarne in #20582
• [Security] Make P/Invokes in [Sec]Trust.cs have blittable signatures. by @rolfbjarne in #20595
• [Security] Make P/Invokes in Certificate.cs have blittable signatures. by @rolfbjarne in #20571
• [Security] Make remaining P/Invokes have blittable signatures. by @rolfbjarne in #20618
• [src] Expand multi-field single statements into multiple statements. by @rolfbjarne in #20489
• [src] Fix accidental xml documentation comments. by @rolfbjarne in #20637

New Contributors

• @Youssef1313 made their first contribution in #20540

Full Changelog: dotnet-9.0.1xx-preview4-9523...dotnet-9.0.1xx-preview5-9639