ASP.Net Core

• ASP.NET Core is a free and open-source web framework and successor to ASP.NET
• It is a modular framework that runs on both the full .NET Framework and the cross-platform .NET Core
• Cross-platform framework for building modern cloud based internet connected applications, such as web apps, IoT apps and mobile backends
• It consists of modular components with minimal overhead, so you retain flexibility while constructing your solutions
• ASP.NET allows you to build high-performance, cross-platform web applications. Patterns like MVC and built-in support for Dependency Injection allow you to build applications that are easier to test and maintain

Request response pipeline

Middleware pipeline

Flow:

• The Kestrel Web server picks up the Request and creates the httpContext and passes it to the First Middleware in the request pipeline
• Order Matters: middleware is executed in the same order in which they are added in the pipeline. The order is critical for security, performance, and functionality
• https://docs.microsoft.com/en-us/aspnet/core/fundamentals/middleware/?view=aspnetcore-3.1#order
• Startup.Configure(IApplicationBuilder) to configure an application’s pipeline
  • The UseXXX and RunXXX method extensions allow us to register the Inline Middlewares to the Request pipeline
  • The RunXXX method adds the terminating middleware while middleware added by UseXXX passes to nex/previous middleware

Startup.cs

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        //...
    }

    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        app.Use(async (context, next) =>
        {
            await context.Response.WriteAsync("");
        });

        app.Run(async (context) =>
        {
            await context.Response.WriteAsync("");
        });
    }
}

App execution