How to get name of roles in Views from IdentityUser in asp.net mvc?

Question

I am trying to display a list of Roles in my index view but there seems to be no possible way to access dbo.AspNetRoles??

ROLE MAINTENANCE CONTROLLER:

namespace DwBusService.Controllers
{
    public class DwRoleMaintenanceController : Controller
    {
        // private readonly ApplicationDbContext _context;
        private readonly RoleManager<IdentityRole> roleManager;
        private readonly UserManager<ApplicationUser> userManager;

        public DwRoleMaintenanceController(RoleManager<IdentityRole> roleManager, UserManager<ApplicationUser> userManager)
        {
            this.roleManager = roleManager;
            this.userManager = userManager;
        }

        // GET: DwRoleMaintenance
        public async Task<IActionResult> Index()
        {
            var roles = roleManager.Roles.OrderBy(a => a.Name);
            return View(roles);
        }
    }
}

APPLICATION USER MODEL

namespace DwBusService.Models
{
    // Add profile data for application users by adding properties to the ApplicationUser class
    public class ApplicationUser : IdentityUser
    {
        public ApplicationUser()
        {
        }
        [Display(Name = "Local Authentication")]
        public bool LocalAuthentication { get; set; }
    }
}

INDEX ROLE MAINTENANCE VIEW

@model IEnumerable<DwBusService.Models.ApplicationUser>
....
<table class="table">
    <thead>
        <tr>
            <th>@Html.DisplayNameFor(model => model.Roles)</th>
            <th></th>
        </tr>
    </thead>
    <tbody>
    @foreach (var item in Model) {
        <tr>
            <td>@Html.DisplayFor(modelItem => item.Roles)</td>
            <td>
                <a asp-action="Edit" asp-route-id="@item.Id">Edit</a> |
                <a asp-action="Details" asp-route-id="@item.Id">Details</a> 
                <a asp-action="Delete" asp-route-id="@item.Id">Delete</a>
            </td>
        </tr>
    }
    </tbody>
</table>

I cannot access Roles.Name or Roles.Id from item.Roles. I have tried to create a virtual RoleNavigation property in Application user, I have tried to make my own IdentityRole.cs model, I have tried many things. Can anyone help me? When I run this code as is I get this error:

InvalidOperationException: The model item passed into the ViewDataDictionary is of type 'Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable'1[Microsoft.AspNetCore.Identity.EntityFrameworkCore.IdentityRole]', but this ViewDataDictionary instance requires a model item of type 'System.Collections.Generic.IEnumerable'1[DwBusService.Models.ApplicationUser]'.

DBO.ASPNETROLES.SQL

CREATE TABLE [dbo].[AspNetRoles] (
    [Id]               NVARCHAR (450) NOT NULL,
    [ConcurrencyStamp] NVARCHAR (MAX) NULL,
    [NormalizedName]   NVARCHAR (256) NULL,
    CONSTRAINT [PK_AspNetRoles] PRIMARY KEY CLUSTERED ([Id] ASC)
);


GO
CREATE NONCLUSTERED INDEX [RoleNameIndex]
    ON [dbo].[AspNetRoles]([NormalizedName] ASC);

Answer 1

Read this first: http://www.c-sharpcorner.com/UploadFile/asmabegam/Asp-Net-mvc-5-security-and-creating-user-role/

If you have done something similar to this then this is what I am doing to get the roles associated with a user plus getting a list of all roles available:

public ActionResult GetRoles(string UserName)
    {
        if (!string.IsNullOrWhiteSpace(UserName))
        {
            Models.ApplicationUser user = context.Users.Where(u => u.UserName.Equals(UserName, StringComparison.CurrentCultureIgnoreCase)).FirstOrDefault();
            var account = new AccountController(HttpContext.GetOwinContext().GetUserManager<ApplicationUserManager>(), null);

            ViewBag.RolesForThisUser = account.UserManager.GetRoles(user.Id);

            // prepopulate roles for the view dropdown
            var list = context.Roles.OrderBy(r => r.Name).ToList().Select(rr => new SelectListItem { Value = rr.Name.ToString(), Text = rr.Name }).ToList();
            ViewBag.Roles = list;
        }

        return View("ManageUserRoles");
    }

Maybe this code will give you some ideas :)....I should have created a ViewModel to contain the results...but I lazily used ViewBag instead.

On the View side, here is the code that utilized the list:

        @Html.AntiForgeryToken()
        @Html.ValidationSummary(true)
        <div class="col-sm-6"  >
                <h3>Add Role to @Model.UserName</h3>
                @Html.Hidden("UserID", Model.Id)
            <span style="font-size:large">Role Name:</span>    @Html.DropDownList("RoleName", (IEnumerable<SelectListItem>)ViewBag.Roles, "Select ...")
            <input class="btn-sm btn-default" type="submit" value="Save" />
        </div>