Controllers

What is it?

In a MVC application, the controller is the layer responsible for receiving all HTTP requests from the user, interpreting it, requesting data from the model, and returning it to the view. In other words, it connects the view and the model.

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ASP.NET Controllers

In ASP.NET, a controller is a class derived from the Microsoft.AspNetCore.Mvc.Controller class, used to define a set of related methods called actions. An action is any public method defined inside the controller.

An sample controller that returns the index view, with an arbitrary action in ASP.NET MVC, can be defined with:

using Microsoft.AspNetCore.Mvc;
 
namespace BookProject
{
    public class HomeController : Controller
    {
        // GET: HomeController
        public ActionResult Index()
        {
            return View();
        }
 
        // GET: Home/SecondAction/id
        public string SecondAction(int id)
        {
            return $"{id} squared: {id * id}";
        }
    }
}