ASP.NET Core in .NET 8 is your complete solution for modern web development. It handles all of your web development needs from the frontend to the backend. You can build beautiful, richly interactive web experiences with Blazor, and high-performance backend APIs and services that are reliable and secure. ASP.NET Core in .NET 8 is perfect for building cloud-native apps, and great tooling in Visual Studio and Visual Studio Code supercharges your productivity. With ASP.NET Core in .NET 8, every developer is a full stack developer! 

The .NET 7.0.201 release is available for download. This SDK includes the previously released .NET 7.0.3 Runtime and is in support of Visual Studio 17.5 release.  

You can use the Themes of .NET Tool (themesof.net) to identify roadmaps and progress on various .NET releases. 

Here’s a summary of what’s new in this preview release:

• Improved startup debugging experience
• Blazor
  • Form model binding & validation with server-side rendering
  • Enhanced page navigation & form handling
  • Preserve existing DOM elements with streaming rendering
  • Specify component render mode at the call site
  • Interactive rendering with Blazor WebAssembly
  • Sections improvements
  • Cascade query string values to Blazor components
  • Blazor Web App template option for enabling server interactivity
  • Blazor template consolidation
• Metrics
  • Testing metrics in ASP.NET Core apps
  • New, improved, and renamed counters
• API authoring
  • Complex form binding support in minimal APIs
• Servers & middleware
  • HTTP.sys kernel response buffering
  • Redis-based output-cache
   

using System.Diagnostics.CodeAnalysis;

namespace CS8Tests;

[Experimental(diagnosticId: "Test001")]
public class ExperimentalAttributeDemo
{
    public void Print()
    {
        Console.WriteLine("Hello Experimental Attribute");
    }
}

var experimentalAttributeDemo = new ExperimentalAttributeDemo();

error Test001: 'CS8Tests.ExperimentalAttributeDemo' is for evaluation purposes only
and is subject to change or removal in future updates. Suppress this diagnostic to proceed.

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net8.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>

    <NoWarn>Test001</NoWarn>
  </PropertyGroup>
</Project>

#pragma warning disable Test001
var demo = new ExperimentalAttributeDemo();
#pragma warning restore Test001

using System.Diagnostics.CodeAnalysis;

namespace CS8Tests;

[Experimental(diagnosticId: "Test001")]
public class ExperimentalAttributeDemo
{
    [Experimental(diagnosticId: "Test002")]
    public void Print()
    {
        Console.WriteLine("Hello Experimental Attribute");
    }
}

var demo = new ExperimentalAttributeDemo();
demo.Print();

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net8.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>

    <NoWarn>Test001,Test002</NoWarn>
  </PropertyGroup>
</Project>

#pragma warning disable Test001,Test002
var demo = new ExperimentalAttributeDemo();
demo.Print();
#pragma warning restore Test001,Test002

.NET 8 is shaping up to be a significant release for Blazor, and there’s one big reason why. 

Experiments with the new WASI workload in .NET 8 Preview 4
.NET 8 adds a new "wasi-experimental" workload, replacing the earlier Wasi.Sdk. This is a step towards giving .NET native, built-in support for server-side WebAssembly scenarios.
This video shows how to get started, then demonstrates how .NET+WASI creates possibilities for new kinds of apps and new ways to use .NET. 

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp3.0</TargetFramework>
  </PropertyGroup>
</Project>

<Project Sdk="Microsoft.NET.Sdk"> 
   <PropertyGroup> 
      <OutputType>Exe</OutputType> 
      <TargetFramework>netcoreapp3.0</TargetFramework> 
      <LangVersion>preview</LangVersion> 
   </PropertyGroup>
 </Project>

<Project Sdk="Microsoft.NET.Sdk"> 
   <PropertyGroup> 
      <OutputType>Exe</OutputType> 
      <TargetFramework>netcoreapp3.0</TargetFramework> 
      <LangVersion>8.0</LangVersion> 
   </PropertyGroup>
</Project>

> dotnet --list-sdks

> dotnet new globaljson --sdk-version 2.2.300
> type global.json

As with every .NET release, Microsoft improves the performance of the runtime and guess what: This release is no exception to this. In this blog post, I want to go through some of the improvements made so far (.NET 8 preview 3).