Development environment: Visual Studio 2022 Preview, .NET 6 , React 17. Create project

Press F5 to run debug, result

Write first custom middleware, with the presence of AI for Intelli Sense, AI suggesion works as I expected.

Write CustomLogger.cs

namespace ReactNET6
{
    public class CustomLogger
    {
        private readonly RequestDelegate _next;

        public CustomLogger(RequestDelegate next)
        {
            _next = next ?? throw new ArgumentNullException("next");
        }

        public async Task Invoke(HttpContext httpContext)
        {
            if (httpContext == null) throw new ArgumentNullException(nameof(httpContext));
            await _next(httpContext);
        }
    }

    public static class MiddlewareExtensions
    {
        public static IApplicationBuilder UseCustomLogger(this IApplicationBuilder app)
        {
            return app.UseMiddleware<CustomLogger>();
        }
    }
}

Add 2 lines (line 1 and line 11) to file Program.cs This is feature called "Top-level statements" in C# 9 https://docs.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-9#top-level-statements

We have Program.cs with content

using ReactNET6;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.

builder.Services.AddControllersWithViews();

var app = builder.Build();

app.UseCustomLogger();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();


app.MapControllerRoute(
    name: "default",
    pattern: "{controller}/{action=Index}/{id?}");

app.MapFallbackToFile("index.html"); ;

app.Run();

Publish

Result after publishing: C:\Users\donhuvy\source\repos\ReactNET6\bin\Release\net6.0\publish , run file ReactNET6.exe , go to http://localhost:5000 to see the result.