I have Error in viewModel ASP.NET MVC C#

Question

What I looked for, we used viewmodel to then access in the view several models, my problem is that I have an error that does not allow me to access the Model. And everywhere I look, I can’t figure out where I’m going wrong. Viewmodel:

 public class ViewModel
{
    public List<Category> Categories { get; set; } = new List<Category>();
    public List<Ad> Ads { get; set; } = new List<Ad>();
}

Controller:

public class ViewModelController : Controller
{
    private LivrinhosContext db = new LivrinhosContext();
    // GET: ViewModel
    public ActionResult Index()
    {
        ViewModel mymodel = new ViewModel();

        mymodel.Categories = db.Categories.ToList(); //Get all categories
        mymodel.Ads = db.Ads.Take(1).OrderByDescending(x => x.BookID).ToList(); //get last ad 

        return View(mymodel);
    }
}

The view:

    @model IEnumerable<LivrinhosMVC.DAL.ViewModel>
@{
    ViewBag.Title = "Home Page";
}
<div class="container">
    <div class="row" style="margin:2em 0">
        <div class="col-sm-4">
            @Html.Label("Categorias")
            <table class="table-condensed">
                @foreach (var category in Model.Categories) {
                    <tr>
                        <td>@Html.ActionLink(category.Name, "../Category/Books", new { id = category.ID }, null)</td>
                    </tr>
                }
            </table>
        </div>
        <div class="col-sm-8" style="display:inline">
            @Html.TextBox("BookTitle", null, new { placeholder = "Título...", @class = "form-control" })
            @Html.DropDownList("Cities", "Portugal")
            @Html.ActionLink("Pesquisar", "Books", null, null, new { @class = "btn btn-primary" })

        </div>
        <div class="row">
            @foreach (var ad in Model.Ads)
            {
                <div class="col-sm-3">


                    @Html.Label(ad.Title)
                    </div>
                }
            </div>
        </div>
    </div>

Answer 1

The problem is you’re returning a ViewModel for your view that actually expects to receive a IEnumerable<ViewModel>.

Review the model of his view. Correct for her to receive the value returned in ViewModelController is:

@model LivrinhosMVC.DAL.ViewModel

Otherwise you need to review your Viewmodel and your Controller to make a type upload IEnumerable<ViewModel>.

Answer 2

Why not create the viewModel with whole object of Category and Ad

public class ViewModel
{
    public Category Categories  { get; set; }
    public Ad Ads  { get; set; }
}