ASP.NET Core MVC

In ASP.NET Core MVC, a controller is a class that handles incoming HTTP requests, processes user input, interacts with a model, and selects a view to render the response.

using Microsoft.AspNetCore.Mvc;

namespace MyApp.Controllers
{
    public class HomeController : Controller
    {
        // Action method for the Home page
        public IActionResult Index()
        {
            return View();
        }

        // Action method that receives a route parameter
        public IActionResult Details(int id)
        {
            var model = GetItemById(id);
            return View(model);
        }
    }
}

An action method is a public method on a controller that can be invoked via a URL. By default, action methods return an IActionResult which can be a view, JSON, redirect, etc.

[HttpPost]
public IActionResult Create(Product model)
{
    if (ModelState.IsValid)
    {
        _repository.Add(model);
        return RedirectToAction(nameof(Index));
    }
    return View(model);
}

The default routing pattern maps URLs to controller actions in the form /[controller]/[action]/{id?}. You can customize routes with attributes.

[Route("products/{id:int}")]
public IActionResult Details(int id) { /* ... */ }

[HttpGet("search")]
public IActionResult Search(string term) { /* ... */ }

Enter a product ID to see how the Details action would be called.