Problem with get/read Related Data in ASP.NET Core 6.0 - asp.net-core-mvc

Question

I'm trying to visualize the data related countries for the current continent in continent details page.
If we use Razor pages the functional looks like this:
public async Task<IActionResult> OnGetAsync(string id)
{
Continent = await _context.Continents
.Include(c => c.Countries)
.AsNoTracking()
.FirstOrDefaultAsync(m => m.ID == id);
if (Continent == null)
{
return NotFound();
}
return Page();
}
I'm trying to make same request in an ASP.NET Core MVC controller:
public async Task<IActionResult> Details(string id)
{
if (id == null || _context.Continents == null)
{
return NotFound();
}
var continent = await _context.Continents
.Include(x => x.Countries)
.AsNoTracking()
.FirstOrDefaultAsync(m => m.ID == id);
if (continent == null)
{
return NotFound();
}
return View(continent);
}
But the Countries is marked as red:
Error CS1061
'Continent' does not contain a definition for 'Countries' and no accessible extension method 'Countries' accepting a first argument of type 'Continent' could be found (are you missing a using directive or an assembly reference?)
C:\Users\Partsmaster\source\repos\RazorCountry\RazorCountry\Controllers\ContinentsController.cs
How I should modify read related data in the ASP.NET Core MVC controller correctly?
ContinentController.cs:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.EntityFrameworkCore;
using RazorCountry.Data;
using RazorCountry.Models;
using RazorCountry.Models.ViewModels;
namespace RazorCountry.Controllers
{
public class ContinentsController : Controller
{
private readonly AppDbContext _context;
public ContinentsController(AppDbContext context)
{
_context = context;
}
// GET: Continents
public async Task<IActionResult> Index(string searchString, string chosenFilter)
{
var viewModel = new ContinentViewModel();
IQueryable<Continent> continents = _context.Continents;
if (!String.IsNullOrEmpty(searchString))
{
switch (chosenFilter)
{
case "id":
viewModel.Filter = "id";
continents = continents.Where(s => s.ID.Contains(searchString));
break;
case "name":
viewModel.Filter = "name";
continents = continents.Where(s => s.Name.Contains(searchString));
break;
}
}
viewModel.Continents = continents;
viewModel.SearchString = searchString;
return View(viewModel);
}
// GET: Continents/Details/5
public async Task<IActionResult> Details(string id)
{
if (id == null || _context.Continents == null)
{
return NotFound();
}
var continent = await _context.Continents.Include(x => x.Countries).AsNoTracking()
.FirstOrDefaultAsync(m => m.ID == id);
if (continent == null)
{
return NotFound();
}
return View(continent);
}
// GET: Continents/Create
public IActionResult Create()
{
return View();
}
// POST: Continents/Create
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Create([Bind("ID,Name")] Continent continent)
{
if (ModelState.IsValid)
{
_context.Add(continent);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
return View(continent);
}
// GET: Continents/Edit/5
public async Task<IActionResult> Edit(string id)
{
if (id == null || _context.Continents == null)
{
return NotFound();
}
var continent = await _context.Continents.FindAsync(id);
if (continent == null)
{
return NotFound();
}
return View(continent);
}
// POST: Continents/Edit/5
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Edit(string id, [Bind("ID,Name")] Continent continent)
{
if (id != continent.ID)
{
return NotFound();
}
if (ModelState.IsValid)
{
try
{
_context.Update(continent);
await _context.SaveChangesAsync();
}
catch (DbUpdateConcurrencyException)
{
if (!ContinentExists(continent.ID))
{
return NotFound();
}
else
{
throw;
}
}
return RedirectToAction(nameof(Index));
}
return View(continent);
}
// GET: Continents/Delete/5
public async Task<IActionResult> Delete(string id)
{
if (id == null || _context.Continents == null)
{
return NotFound();
}
var continent = await _context.Continents
.FirstOrDefaultAsync(m => m.ID == id);
if (continent == null)
{
return NotFound();
}
return View(continent);
}
// POST: Continents/Delete/5
[HttpPost, ActionName("Delete")]
[ValidateAntiForgeryToken]
public async Task<IActionResult> DeleteConfirmed(string id)
{
if (_context.Continents == null)
{
return Problem("Entity set 'AppDbContext.Continents' is null.");
}
var continent = await _context.Continents.FindAsync(id);
if (continent != null)
{
_context.Continents.Remove(continent);
}
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
private bool ContinentExists(string id)
{
return _context.Continents.Any(e => e.ID == id);
}
}
}
Try to understand "read related data". May be I need to add some ViewModel and rewrite the Details script?
Continent.cs:
using System.ComponentModel.DataAnnotations;
namespace RazorCountry.Models
{
public class Continent
{
[Required, StringLength(2, MinimumLength = 2), Display(Name = "Code")]
[RegularExpression(#"[A-Z]+", ErrorMessage = "Only upper case characters are allowed.")]
public string ID { get; set; }
[Required, Display(Name = "Continent")]
public string Name { get; set; }
}
}
Country.cs:
using Microsoft.AspNetCore.Mvc.Rendering;
using System.ComponentModel.DataAnnotations;
namespace RazorCountry.Models
{
public class Country
{
[Required]
[StringLength(2, MinimumLength = 2)]
[RegularExpression(#"[A-Z]+", ErrorMessage = "Only upper case characters are allowed.")]
[Display(Name = "Code")]
public string ID { get; set; }
[Required]
[RegularExpression(#"[A-Z]+", ErrorMessage = "Only upper case characters are allowed.")]
[Display(Name = "Continent")]
public string ContinentID { get; set; }
[Required]
[Display(Name = "Country")]
public string Name { get; set; }
[Range(1, 10000000000)]
[DisplayFormat(DataFormatString = "{0:N0}", ApplyFormatInEditMode = true)]
public int Population { get; set; }
public int Area { get; set; }
[Display(Name = "UN Date")]
[DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
[DataType(DataType.Date)]
public DateTime UnitedNationsDate { get; set; }
}
}