Asp.Net Core 3.1 Web Application, Api page not found issue - asp.net-core

Question

My Environment Windows 10. Visual Studio 2019 Professional, Asp.Net Core 3.1
I am following a Pluralsight course to teach myself Asp.Net Core 3.1. Following the instructor, I have created the web application. Everything goes well until the instructor adds an api controller to the application. It works for him but not for me.
Here's my api controller
namespace OdeToFood.Api
{
[Route("api/[controller]")]
[ApiController]
public class RestaurantsController : ControllerBase
{
private readonly OdeToFoodDbContext _context;
public RestaurantsController(OdeToFoodDbContext context)
{
_context = context;
}
// GET: api/Restaurants
[HttpGet]
public async Task<ActionResult<IEnumerable<Restaurant>>> GetRestaurants()
{
return await _context.Restaurants.ToListAsync();
}
// GET: api/Restaurants/5
[HttpGet("{id}")]
public async Task<ActionResult<Restaurant>> GetRestaurant(int id)
{
var restaurant = await _context.Restaurants.FindAsync(id);
if (restaurant == null)
{
return NotFound();
}
return restaurant;
}
. . . . .
Here's my project structure and hierarchy.
When I rebuild my project, and call the app from local IIS Express, i.e. https://localhost:44351/ It loads fine. I can interact fully, browse and CRUD entities. However when I point to any api url, e.g. https://localhost:44351/api/Restaurants or https://localhost:44351/api/Restaurants/2 I get "This localhost page can’t be found". The api simply does not load or respond in any way.
I am familiar with MVC5 where, when creating a new project, in the create project wizard scaffolding, you could check a box to add api functionality. I am not seeing this in VS2019 for Asp.Net Core 3.1 We Apps.
I promise you have have done my homework before asking this question here. I have googled to death. I have seen MS articles on core 3.1 breaking changes. I have looked at online project templates. I have searched stackoverflow. Maybe my search terms are flawed and I'm simply missing something simple.
Questions:
Why is the api shown above not loading?
Is there a way to add api functionality to an existing Asp.Net Core 3.1 Web Application or do I need to create a separate api project?
Is there a way to create a new Asp.Net Core 3.1 Web Application with api functionality included?
My thanks in advance
Kieran

Answer 1

If you'd like to add web APIs feature into an existing Razor Pages project, you need to do additional configuration, like below.
public void ConfigureServices(IServiceCollection services)
{
//add services for controllers
services.AddControllers();
services.AddRazorPages();
//...
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
//...
app.UseRouting();
//...
app.UseEndpoints(endpoints =>
{
//add endpoints for controller actions
endpoints.MapControllers();
endpoints.MapRazorPages();
});
}
Testing code of controller and action(s)
[Route("api/[controller]")]
[ApiController]
public class RestaurantsController : ControllerBase
{
public IActionResult GetRestaurants()
{
return Ok("Restaurants List Here");
}
}
Test Result