如何在 .net mvc 中更改 mvc controller 的区域？

Question

I have created new 'Admin' area , and i want to move there old two controllers with their views.( RoleManagerController, UserRolesController ) I tried to cut and paste all the files and it didnt work. Then i tried deleting old files and creating new controllers by clicking on ' add new controlle r' and creating new views by rigth clicking on controller methods and selecting 'Create view' , it didnt work as well.

Here is my project structure :

I have moved two controllers: RoleManagerController , UserRolesController from ~/Controllers to ~/Areas/Admin/Controllers . And their views from ~/Views to ~/Areas/Admin/Views .

When i try to access: localhost://Admin/RoleManager or localhost://Admin/UserRoles i get 404 HttpError :

If i try to acces their old routes: 'localhost://UserRoles' and 'localhost://RoleManager' i get next errors:

It seems that even thought i have deleted and created a new controllers in the new area, routing got unchanged. here is my 'program.cs' file:

using HotelReservationSystem.Data;
using HotelReservationSystem.Models;
using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
var connectionString = builder.Configuration.GetConnectionString("DefaultConnection");
builder.Services.AddDbContext<ApplicationDbContext>(options =>
    options.UseSqlServer(connectionString));
builder.Services.AddIdentity<ApplicationUser, IdentityRole>()
    .AddEntityFrameworkStores<ApplicationDbContext>()
    .AddDefaultUI()
    .AddDefaultTokenProviders();
builder.Services.AddDatabaseDeveloperPageExceptionFilter();

builder.Services.AddControllersWithViews();

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.UseMigrationsEndPoint();
}
else
{
    app.UseExceptionHandler("/Home/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseStaticFiles();

app.UseRouting();

app.UseAuthentication();
app.UseAuthorization();


app.UseEndpoints(endpoints =>
{
    endpoints.MapControllerRoute(
      name: "Admin",
      pattern: "{area:exists}/{controller=Home}/{action=Index}/{id?}"
    );
    app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Home}/{action=Index}/{id?}");
    app.MapRazorPages();

});

//Seeding user Roles and Default admin user
using (var scope = app.Services.CreateScope())
{
    var services = scope.ServiceProvider;
    var loggerFactory = services.GetRequiredService<ILoggerFactory>();
    try
    {
        var context = services.GetRequiredService<ApplicationDbContext>();
        var userManager = services.GetRequiredService<UserManager<ApplicationUser>>();
        var roleManager = services.GetRequiredService<RoleManager<IdentityRole>>();
        await ContextSeed.SeedRolesAsync(userManager, roleManager);
        await ContextSeed.SeedSuperAdminAsync(userManager, roleManager);
    }
    catch (Exception ex)
    {
        var logger = loggerFactory.CreateLogger<Program>();
        logger.LogError(ex, "An error occurred seeding the DB.");
    }
}

app.Run();

/Areas/Admin/Controllers/RoleManagerController.cs

using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;

namespace HotelReservationSystem.Areas.Admin.Controllers
{
    public class RoleManagerController : Controller
    {
        private readonly RoleManager<IdentityRole> _roleManager;
        public RoleManagerController(RoleManager<IdentityRole> roleManager)
        {
            _roleManager = roleManager;
        }
        public async Task<IActionResult> Index()
        {
            var roles = await _roleManager.Roles.ToListAsync();
            return View(roles);
        }
        [HttpPost]
        public async Task<IActionResult> AddRole(string roleName)
        {
            if (roleName != null)
            {
                await _roleManager.CreateAsync(new IdentityRole(roleName.Trim()));
            }
            return RedirectToAction("Index");
        }
    }
}

/Areas/Admin/Views/RoleManager/index.cshtml :

    ViewData["Title"] = "Role Manager";
    Layout = "~/Views/Shared/_Layout.cshtml";
}
<h1>Менеджер ролей</h1>
<form method="post" asp-action="AddRole" asp-controller="RoleManager">
    <div class="input-group">
        <input name="roleName" class="form-control w-25">
        <span class="input-group-btn">
            <button class="btn btn-primary">Добавить новую роль</button>
        </span>
    </div>
</form>
<table class="table table-striped">
    <thead>
        <tr>
            <th>Id</th>
            <th>Роль</th>
        </tr>
    </thead>
    <tbody>
        @foreach (var role in Model)
        {
            <tr>
                <td>@role.Id</td>
                <td>@role.Name</td>
            </tr>
        }
    </tbody>
</table>

Answer 1

You have to add Area attribute on top of your controller class to associate the controller with the area. Eg

[Area("RoleManager")]
public class RoleManagerController : Controller
{
}

For more detail refer: https://docs.microsoft.com/en-us/aspnet/core/mvc/controllers/areas?view=aspnetcore-6.0