.NET 10 Preview 4

[jamesmontemagno]

Today, we are excited to announce the fourth preview release of .NET 10 with enhancements across the .NET Runtime, SDK, libraries, C#, ASP.NET Core, Blazor, .NET MAUI, and more. Check out the full release notes linked below and get started today.

Download .NET 10 Preview 4

This release contains the following improvements.

📚Libraries

• Add Out-of-Proc Trace Support for Activity Events and Links
• Rate Limiting Trace Sampling Support
• New async Zip APIs
• Performance improvement in GZipStream for concatenated streams
• Full Release Notes

⏱️Runtime

• Escape Analysis for Local Struct Fields
• Inlining Improvements
• Full Release Notes

🛠️ SDK

• No new features added in this preview release.

C#

• No new features added in this preview release.

F#

This release you will find updates across the F# language, FSharp.Core standard library, and FSharp.Compiler.Service.

Visual Basic

• No new features added in this preview release.

🌐 ASP.NET Core & Blazor

• JSON Patch with System.Text.Json
• Minimal API validation for record types
• Generate OpenAPI schemas in transformers
• Improved OpenAPI XML documentation support
• Access the OpenAPI document with IOpenApiDocumentProvider
• OpenAPI.NET updated to Preview.17
• JavaScript interop for constructors and properties
• Reference a JavaScript function with IJSObjectReference
• Blazor WebAssembly runtime diagnostics
• Signal Not Found responses using NavigationManager
• NavigationManager.NavigateTo no longer throws a NavigationException
• QuickGrid method CloseColumnOptionsAsync renamed to HideColumnOptionsAsync
• WriteImportMapToHtml renamed to OverrideHtmlAssetPlaceholders
• Preload Blazor framework static assets
• Blazor WebAssembly Standalone App template updates
• Blazor boot manifest merged into dotnet.js
• Use WebApplicationFactory with Kestrel for integration testing
• Full Release Notes

📱 .NET MAUI

• MediaPicker modernization
• Nullable Pickers
• Full Release Notes
• Full list of quality improvements on dotnet/maui GitHub releases.

🤖 .NET for Android

• Use System.IO.Compression for .apk creation
• Reduced download size
• Full list of quality improvements on dotnet/android GitHub releases.

🍎 .NET for iOS, Mac Catalyst, macOS, tvOS

This release was focused on quality improvements and build performance. A detailed list can be found on dotnet/macios GitHub releases including a list of Known issues.

🖥️ Windows Forms

This release introduced shared core clipboard functionality with WPF and was focused on several quality and engineering improvements. See the full release notes for details.

🖥️ Windows Presentation Foundation (WPF)

• API Enhancements
• Shared Clipboard Code
• Fluent Theme Bug Fixes and Enhancements
• Performance Improvements
• Full Release Notes for details.

🎁 Entity Framework Core

• Full-text search support on Azure Cosmos DB for NoSQL
• Hybrid search
• Vector similarity search exits preview
• Several small improvements
• Full Release Notes

📦 Container Images

• No new features added in this preview release.

🚀 Get started

To get started with .NET 10, install the .NET 10 SDK.

If you're on Windows using Visual Studio, we recommend installing the latest Visual Studio 2022 preview. You can also use Visual Studio Code and the C# Dev Kit extension with .NET 10.

🔔 Stay up-to-date with .NET 10

You can stay up-to-date with all the features of .NET 10 with:

• What's new in .NET 10
• What's new in C# 14
• What's new in .NET MAUI
• What's new in ASP.NET Core
• What's new in Entity Framework Core
• What's new in Windows Forms
• What's new in WPF
• Breaking Changes in .NET 10
• .NET 10 Releases

Additionally, be sure to subscribe to the GitHub Discussions RSS news feed for all release announcements.

[ejritter]

Love seeing the push to make CollectionView the standard. So many views deprecated!

[sofiageo]

Why isn't there any release tags for this preview? I watch the releases through github but this time there wasn't any.

edit: I can see the tag now, maybe something was stuck or it was added later.

[ReneeGA2020]

This preview seems break the compilation of WinUI projects. I now get an error of csc.dll does not exist every time I try to build my WinUI projects.

1>C:\Program Files\Microsoft Visual Studio\2022\Preview\MSBuild\Current\Bin\amd64\Microsoft.CSharp.CurrentVersion.targets(238,5): error : The application to execute does not exist: 'C:\Program Files\dotnet\sdk\10.0.100-preview.4.25258.110\Roslyn\binfx\csc.dll'

[HotCakeX]

Known issue, there is a workaround: https://github.com/dotnet/core/blob/main/release-notes/10.0/known-issues.md#maui-applications-may-fail-to-build-in-visual-studio

Using dotnet CLI works without the workaround, e.g. dotnet publish

[ReneeGA2020]

Thank you, I first tried PropertyGroup workarounds, but it does not seem to work.

The dotnet build /p:Platform=x64 works for most of the WinUI projects, except one of them reports an error says Could not load file or assembly 'C:\Program Files\dotnet\sdk\10.0.100-preview.4.25258.110\Microsoft\VisualStudio\v17.0\AppxPackage\Microsoft.Build.Packaging.Pri.Tasks.dll'.
Perhaps it's a issue of winUI itself when compiled with CLI.