.NET 6 First Look

Overview

• .NET 6 is a unification platform of different .NETs into one, with a single BCL and SDK
• Visual Studio 2022 is now x64 and has a Hot Reload feature for UIs (avoiding restarts)
• C# 10 with new top-level statements, ASP.NET Core 6, EF Core 6, and C++ updates
• ASP.NET template updates for MVC, Razor Pages, Angular, React and other JS frameworks
• New Minimal APIs and Blazor extensions, WebAssembly Ahead-of-time (AOT) compilation
• Maui (RC1), a cross-platform native UI dev platform that evolved from Xamarin.Forms
• Big overall performance improvements, especially around file I/O (FileStream rewrite)

Recources

• Pluralsight
  •  .NET 6 First Look by Gill Cleeren
• Blogs
  • Announcing .NET 6 — The Fastest .NET Yet by Richard Lander
  • What’s new in C# 10 by Microsoft

Visual Studio 2022

• A new refreshed UI, with new icons, new font (Cascadia), and coloured tabs by project
• Visual Studio is now using x64 architecture!
• A new Hot Reload feature/ button for running apps – no more stopping and rebuilding projects while debugging! Code changes are visible in running apps right away
  • Hot Reload is available for WPF, Blazor, and ASP.NET Core MVC with CSS
  • Hot Reload can also be bound to the Save button
• New and updated project templates, including ASP.NET Core 6 and Angular
  • E.g., top level statements in Program.cs
    • Startup.cs + Prgram.cs = Program.cs
• IntelliCode – auto code snippets/ templates accessible with a [tab] key
• Refactoring improvements, e.g., sync namespaces, file scope namespaces
• XAML Live Preview, Improved Git experience

C# 10

• Some New Features
  • Global using statements (types available in the entire solution)
    • Note: it’s a good idea to maintain these in GlobalUsings.cs
  • Implicit usings – when enabled there’s no need to ref System; etc.
  • File-scoped namespaces (improved code nesting)
  • Extended property patterns (nested properties or fields within a property pattern)
  • Lambda expressions improvements
  • Const interpolated strings
  • Record structs enhancements (e.g., sealing ToString()) 
  • Generic attributes
  • Assignment and declaration in the same deconstruction
  • AsyncMethodBuilder attribute on methods is now possible
  • DateOnly and TypeOnly data types
  • New Environment API features, including find Process ID and Process Path
  • new LINQ Methods e.g., Chunk() on IEnumerable<>, MinBy() and MaxBy()
  • ThrowIfNull, a new timer, parallel for each async, and more!
• Release Notes on Github

// global namespace
namespace MyNamespace;

// generic attribute example
public class GenericAttribute<T> : Attribute { }

[GenericAttribute<string>()]
public string Method() => default;

// record struct example
public record Person(string FirstName, string LastName);

public static void Main()
{
    Person person = new("Joe", "Doe");
    Console.WriteLine(person); // output: Person { FirstName = Joe, LastName = Doe}

    // assignment and declaration in same deconstruction
    int x = 0;
    (x, int y) = point;
}

ASP.NET Core 6

• ASP.NET Core 6
  • ASP.NET Core MVC – server-side web apps using the MVC model
  • ASP.NET Core Razor Pages – simpler server-side web apps
  • ASP.NET Core Blazor or Blazor – client-side apps with C#
    • Blazor code now compiled into WebAssembly
    • Error boundaries, e.g., at the component level
    • Blazor (cross-platform) MAUI apps, dynamic widgets and more!
  • ASP.NET Core APIs – including minimal API
• Breaking Changes/ Compatibility for upgrading existing apps

Minimal APIs

• A very compact template to create APIs
  • Based on top-level statements and Program.cs
  • More functional approach to building applications than the traditional OOP model