CODEWITHSUNDEEP
c#
oldman
oldman

Reputation: 49

How ASPNET CORE start up to listen httprequest?

well, I am now learning aspnet core , I can't understand when does the application start its server(like IIS or KestrelServer)，and how the server listen the httprequest and forwards the request to the application. can anybody help me? thanks

Upvotes: 4

Views: 1386

Answers (2)

vivek
vivek

Reputation: 1605

ASP.NET Core application anatomy is discussed here at this asp.net core introduction.

Some important text that answers your question is as follows from the tutorial:

An ASP.NET Core app is simply a console app that creates a web server in its Main method. Main uses WebHostBuilder, which follows the builder pattern, to create a web application host. The builder has methods that define the web server (for example UseKestrel) and the startup class (UseStartup). In the example above, the Kestrel web server is used, but other web servers can be specified. The Startup class is where you define the request handling pipeline and where any services needed by the app are configured. The Startup class must be public and contain the following methods:

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

    public void Configure(IApplicationBuilder app)
    {
    }
}

I guess this will help you to understand how asp.net core handles Http requests. Thanks

Upvotes: 1

Tanato
Tanato

Reputation: 1173

Well, let's start from beginning (As I couldn't figure out your knowledge about C#)

Every C# application must contain a single Main method specifying where program execution is to begin, so there it is, by default the templates have a Class Program where you can set the type of WebServer that you'll use, and tell the server to start listening for HTTP requests, something like:

public static void Main(string[] args)
{
    var config = new ConfigurationBuilder()
        .AddCommandLine(args)
        .Build();
    var host = new WebHostBuilder()
                .UseKestrel()
                .UseConfiguration(config)
                .UseStartup<Startup>()
                .Build();
    host.Run();
}

In AspNetCore and even in AspNet (MVC or WebApi) you can (and should) use OWIN (aka Katana or vNext, that are Microsoft's OWIN implementations for AspNet and AspNetCore respectively).

OWIN represents a Interface (just a specification), that tell how WebServers should comunicate with WebApplications. Normally it handle the Http Requests to a pipeline that you can plug Middlewares, like Authentication/Authorization, Log, Error Handlings and so on, and in the end of the pipeline you should plug your Web Application.

In AspNetCore you set your Middleware Pipeline by using UseStartup<MyStartupClass> in your Host configuration see Main method above and simple as that your Pipeline will handle every HttpRequest.

When building a MVC applications in AspNetCore (.UseMvc()) you are setting a middleware that tells your application to look for classes that inherit from Microsoft.AspNetCore.Mvc.Controller to look for RESTful entry points (HTTP GET, POST...)

This is just a simple overview, and you can learn a lot more looking in the documentation of this technologies. Just search for tags like Katana, vNext, OWIN, OWIN Middleware, OWIN Pipeline...

Upvotes: 3

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