What lifecycle methods of requests exist in ASP.NET…

The request lifecycle in ASP.NET Core includes the following stages:

Request Reception: The request arrives at the web server (e.g., Kestrel, IIS).
HttpContext Creation: The web server creates an HttpContext object to represent the current request and response.
Middleware Pipeline: The HttpContext passes through the middleware pipeline. Each middleware can process, modify, or pass the request to the next middleware. The order of middleware is important.
Endpoint Routing: The routing system determines the endpoint (e.g., controller method, Razor Page) based on the request URL.
Endpoint Execution: The endpoint executes. The controller or Razor Page processes the request, performs business logic, and generates a result.
Result Execution: The result (e.g., View, JSON, file) is processed and written to the response.
Response Sending: The constructed response is sent back to the client.

Key components implementing these stages:

Web Server: Receives requests (Kestrel, IIS, Nginx, Apache).
Middleware: Components forming the request processing pipeline (e.g., Static Files Middleware, Authentication Middleware, Routing Middleware).
Routing Middleware: Determines which endpoint will handle the request.
Endpoint Execution: Executes the code associated with the selected endpoint (e.g., controller method, Razor Page handler).
Result Execution: Processes the result returned by the endpoint.

The middleware architecture is a central concept in the request lifecycle in ASP.NET Core. Each middleware is a class with an Invoke or InvokeAsync method that takes an HttpContext and a RequestDelegate delegate (a reference to the next middleware in the pipeline).

public class CustomMiddleware
{
    private readonly RequestDelegate _next;

    public CustomMiddleware(RequestDelegate next)
    {
        _next = next;
    }

    public async Task InvokeAsync(HttpContext context)
    {
        // Logic before the next middleware
        // For example, logging, authentication, authorization

        await _next(context); // Call the next middleware in the pipeline

        // Logic after the next middleware
        // For example, modifying the response, adding headers
    }
}

// Example of registering custom middleware in Startup.Configure
// app.UseMiddleware<CustomMiddleware>();

What lifecycle methods of requests exist in ASP.NET Core?