4. Add Controller

Step 1: Select the EXPLORER icon and then control-click (right-click) Controllers > New File and name the new file HelloWorldController.cs.

Contextual menu

Step 2: Replace the contents of Controllers/HelloWorldController.cs with the following code:

using Microsoft.AspNetCore.Mvc;
using System.Text.Encodings.Web;

namespace MvcMovie.Controllers
{
    public class HelloWorldController : Controller
    {
        // 
        // GET: /HelloWorld/

        public string Index()
        {
            return "This is my default action...";
        }

        // 
        // GET: /HelloWorld/Welcome/ 

        public string Welcome()
        {
            return "This is the Welcome action method...";
        }
    }
}

Output

Append "HelloWorld" to the path in the address bar. The Index method returns a string.

Browser window showing an app response of This is my default action

Step 3: Browse to: https://localhost:5001/HelloWorld/Welcome.