Introduction

The much-anticipated .NET Community Toolkit has released its latest version, 8.4, unveiling a plethora of powerful updates and improvements that are sure to enhance your development experience. This release focuses on vital features including partial properties in the MVVM Toolkit, improved diagnostic analyzers, bug fixes, and other enhancements designed to streamline workflows.

Partial Properties in MVVM Toolkit

One of the standout features of this update is the addition of partial properties within the MVVM Toolkit. This is made possible by the latest C# language features included in the .NET 9 SDK which allow property declarations to be more effectively integrated with the language itself. This means developers can now utilize modifiers like new, sealed, override, and required more intuitively. Moreover, custom attributes and accessibility modifiers can now be applied to properties, fields, or accessors with ease.

The introduction of partial properties significantly enhances nullability annotations and ensures seamless compatibility with Native AOT in both UWP and WinUI 3 applications. Excitingly, a forthcoming Visual Studio update will also facilitate smoother navigation between partial property declarations and their implementations, making development even more efficient.

Code Fixer and Migration Tools

To assist in this transition, a fresh code fixer has been added to Visual Studio, allowing developers to migrate existing [ObservableProperty] fields with a simple click. This migration is highly encouraged for projects utilizing CsWinRT, as it promises improved performance and enhanced language support.

Diagnostic Analyzers Enhancements

In addition to these significant features, version 8.4 introduces a more comprehensive collection of diagnostic analyzers for the MVVM Toolkit. These analyzers target prevalent coding issues, including unsupported types and incorrect declarations, thereby enhancing code quality within MVVM frameworks. New checks included in this release focus on language version compatibility, AOT compatibility for WinRT scenarios, and proper usage of [ObservableProperty] and [RelayCommand].

Project File Adjustments

Developers looking to take full advantage of the new partial properties are advised to adjust their project files to include `<LangVersion>preview</LangVersion>`, ensuring compatibility and access to these advancements.

Additional Features and Enhancements

This release also boasts several additional enhancements such as validating the Windows SDK version through MSBuild logic, supporting forwarding attributes to property accessors, and refining diagnostic suppressions for custom attribute targets. The debugging process sees improvements too, with the embedding of .pdb files for all source generators and analyzers, alongside performance boosts for various toolkit components.

Additionally, the update includes a new AsStream() extension for ReadOnlySequence<byte>, empowering developers to efficiently create read-only, seekable streams. The IndexOf<T> extension now utilizes ref readonly, reinforcing its intended use and performance profile.

Conclusion

With the launch of the .NET Community Toolkit 8.4, developers have more tools at their disposal than ever before—improving efficiency, performance, and overall code quality. Don’t miss out on experiencing these remarkable features that promise to transform your development journey!