You can see more details of the release in the .NET Core 2.2 Preview 3 release notes. Related instructions, known issues, and workarounds are included in the releases notes. 

In .NET 8, we’re investing in improving the debugging experience of commonly used types in .NET apps. These include:

• HttpContext and friends
• WebApplication
• MVC and Razor Pages
• gRPC
• Endpoint metadata
• Logging
• Configuration 

ASP.NET Core 8 and .NET 8 bring many exciting performance improvements. In this blog post, we will highlight some of the enhancements made in ASP.NET Core and show you how they can boost your web app’s speed and efficiency.  

Web API Development in .NET 8 in 2 Hours | ASP.NET CORE | RESTFUL API

00:00:00 Introduction
00:03:06 What is Web API & Why create Web API
00:10:21 How Web API Works in Theory
00:14:49 How Web API Works  (Demo with Minimal APIs)
00:27:32 What is a Web API Framework
00:33:27 ASP.NET Core Middleware Pipeline
00:37:34 Web API Controller
00:42:25 Routing in Web API
00:51:17 Model Binding
01:01:06 Model Validation with DataAnnatation
01:08:07 Model Validation with ValidationAttribute
01:15:10 Web API Return Types
01:21:30 In Mememory Repository
01:25:01 Model Validation with Action Filter
01:35:30 Read Endpoint
01:36:55 Create Endpoint
01:46:45 Validating Create Endpoint with ActionFilter
01:51:23 Update Endpoint
01:59:48 Exception Hanlding with Exception Filter
02:05:48 Delete Endpoint
 

In .NET 8 we plan to add a new project template, Blazor Web Application, that covers all combinations of server-hosted projects (traditional Blazor Server apps, Blazor WebAssembly hosted, and the new unified architecture that allows use of Server, WebAssembly, and SSR in a single project). It will work by multitargeting over net8.0 and net8.0-browser. 

.NET Core

• January 2020 Updates – 2.1.15, 3.0.2, and 3.1.1

• .NET Core 3.1.1 and .NET Core SDK 3.1.101( Release Notes | Download )

• .NET Core 3.0.2 and .NET Core SDK 3.0.102 ( Release Notes | Download )

• .NET Core 2.1.15 and .NET Core SDK 2.1.803 ( Release Notes | Download )

Discover .NET 8 Preview 3! The 7 Features You Need to Know 

• We improved solution load performance by optimizing design time build.
• We've added installation progress details on Visual Studio Installer.
• You can pause your installation and resume at a later time.
• We streamlined the update process so the notification takes you directly to the Installer.
• Non-administrators can create a VS layout.
• We added a new shortcut for Edit.Duplicate in the keyboard mapping.
• We made significant improvements to the F# language and tools, particularly for .NET Core SDK projects.
• The C++ compiler optimizes your code to run faster through improved optimizations.
• C++ Mapfile generation overhead is reduced in full linking scenarios.
• Debug options are available for Embedded ARM GCC support.
• We added strong name signing on CoreCLR for the C# compiler.
• Visual Studio Tools for Xamarin has lots of new productivity updates for iOS and Android developers.
• Python no longer requires a completion DB, and Anaconda users have support for conda.
• The Performance Profiler's CPU Usage Tool can display logical call stacks for asynchronous code.
• The CPU Usage tool displays source line highlighting and async/await code with logical 'Call Stack Stitching'.
• The debugger supports thread names set via SetThreadDescription APIs in dump debugging.
• Snapshot Debugging can be started from the Debug Target dropdown for ASP.NET applications.
• We've launched the initial implementation of Navigate to decompiled sources for .NET code navigation.
• New enhancements for Configure Continuous Delivery include support for TFVC, Git authentication over SSH, and containerized projects.
• You can now click on the Continuous Delivery tile in Team Explorer to configure automated build and deployments for your application.
• Team Explorer supports Git tags and checking out pull request branches.
• Service Fabric Tooling for the 6.1 Service Fabric release is now available.
• The Windows 10 Insider Preview SDK can be installed as an optional component.
• File versions for a number of Visual Studio executables now reflect the minor release.
• Test Explorer has a hierarchy view and real time test discovery is now on by default.
• We have added support for testing Win10 IoT Core applications.
• Visual Studio Build Tools supports TypeScript and Node.js.
• ClickOnce Tools support signing application and deployment manifests with CNG certificate.
• You can access Azure resources such as Key Vault using your Visual Studio accounts.