The .NET world is evolving rapidly, with ASP.NET Core 5 and the subsequent .NET 6 offering a plethora of new features, performance enhancements, and smoother development experiences. In this blog, we’ll briefly touch upon the salient features of these releases and showcase a quick code example to get you started.

ASP.NET Core 5 Highlights:

1. Performance Improvements: ASP.NET Core 5 comes with a host of performance improvements that make it even more efficient, from reduced memory footprints to faster response times.
2. Blazor WebAssembly AOT Compilation: Blazor WebAssembly now supports Ahead-of-Time (AOT) compilation, which can boost the performance of your web apps.
3. Updated SignalR Hub Filters: A new feature that enables developers to run code before and after the invocation of Hub methods.
4. Model Binding Improvements: Enhanced support for C# 9 record types and improved nullable reference type support.

.NET 6 Highlights:

1. Unification of .NET Frameworks: .NET 6 aims to provide a unified platform for all types of .NET applications - from mobile to desktop to cloud.
2. MAUI: The .NET Multi-platform App UI (MAUI) is a modern, cross-platform way to build native UIs for Windows, Android, macOS, and iOS using a single codebase.
3. Enhanced Blazor Features: Improved hot-reload capabilities and better error handling for Blazor.
4. Performance Improvements: Continued advancements in performance across the board, with emphasis on cloud-based applications.

A Simple ASP.NET Core 5 Web API Example:

To provide a flavor of what developing in this environment feels like, let’s set up a basic Web API using ASP.NET Core 5:

// Create a new model called 'Book'
public record Book(int Id, string Title, string Author);

// Create a controller
[ApiController]
[Route("[controller]")]
public class BooksController : ControllerBase
{
    private static readonly List<Book> Books = new List<Book>
    {
        new Book(1, "The Great Gatsby", "F. Scott Fitzgerald"),
        new Book(2, "Moby Dick", "Herman Melville")
    };

    [HttpGet]
    public IEnumerable<Book> GetBooks()
    {
        return Books;
    }

    [HttpGet("{id}")]
    public ActionResult<Book> GetBook(int id)
    {
        var book = Books.FirstOrDefault(b => b.Id == id);
        if (book == null) return NotFound();
        return book;
    }
}

With just a few lines of code, we have set up an API that can fetch details about books.

Conclusion

The advancements in ASP.NET Core 5 and .NET 6 underscore the commitment to enhancing the developer experience, performance, and versatility of .NET applications. The introduction of features like Blazor WebAssembly AOT Compilation, updated SignalR Hub Filters, and the much-anticipated .NET MAUI framework are indicative of the direction in which the .NET ecosystem is headed. Furthermore, the provided ASP.NET Core 5 Web API example demonstrates the simplicity and elegance with which developers can craft efficient APIs. These releases not only bring state-of-the-art functionalities to the table but also pave the way for a more unified, productive, and high-performance development future. For developers entrenched in the .NET world or those considering a foray into it, there’s never been a more exciting time.