"Object reference not set to an instance of an object" When adding to shopping cart

Question

I can't find the solution for my problem, which is as follows: I'm creating an MVC online store in ASP.net. Everything was working fine until I tried putting items in my shopping cart. Then I get the "object reference not set to an instance of an object" error. I've tried several solutions who solved the issue for other users, but without any luck, unfortunately. Please let me know if you need more of My code:

namespace Oblig2.Models
{
    public class HandlevognViewModel
    {
        public List<Handlevogn> VognItems { get; set; }
        public decimal VognTotal { get; set; }
    }
}

@model Oblig2.Models.HandlevognViewModel

@{
    ViewBag.Title = "Handlevogn";
}

<h2>Handlevogn</h2>

<p class="button"> @Html.ActionLink("Til Kassen", "AdresseBetale", "Kassen")</p>

<table>
    <tr> 
        <th>Vare Navn</th>
        <th>Pris </th>
        <th>Antall </th>
    </tr>

    //This is where the error occurs.
    @foreach (var item in Model.VognItems)
    {
        <tr>
            <td>@item.Produkt.VareNavn</td>
            <td>@item.Produkt.Pris</td>
            <td>@item.Antall</td>
        </tr>
    }
</table>

namespace Oblig2.Controllers
{
    public class VarerController : Controller
    {
        private ButikkDBContext db = new ButikkDBContext();

        public ActionResult index()
        {
            return View(db.Produkt.ToList());
        }

        protected override void Dispose(bool disposing)
        {
            db.Dispose();
        }
    }
}

    namespace Oblig2.Controllers
    {
        public class HandlevognController : Controller
        {
            ButikkDBContext db = new ButikkDBContext();

            public ActionResult index()
            {
                var vogn = Vogn.GetVogn(this.HttpContext);

                var viewModel = new HandlevognViewModel
                {
                    VognItems = vogn.GetVognItems(),
                    VognTotal = vogn.GetTotal()
                };

                return View(viewModel);
            }

            public ActionResult LeggTil(int id)
            {
                var nyVare = db.Produkt.Single(vare => vare.VareNr == id);
                var vogn = Vogn.GetVogn(this.HttpContext);
                vogn.LeggTilHandleVogn(nyVare);

                return RedirectToAction("index");
            }

            [ChildActionOnly]
            public ActionResult VognSammendrag()
            {
                var vogn = Vogn.GetVogn(this.HttpContext);
                ViewData["VognAntall"] = vogn.GetAntall();
                return PartialView("VognSammendrag");
            }

        }
   }

Welcome to Stackoverflow. As a start, please read [FAQ] and [ask] couple of times. Second of all, please read first [`What is a NullReferenceException and how do I fix it?`](http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-and-how-do-i-fix-it) — Soner Gönül, Nov 02 '13 at 13:05
Model.VognItems is null. Why are you creating a list in your constructor and not assigning it? — therealtbs, Nov 02 '13 at 13:07
Thank you for answering. @item.Produkt.VareNavn in my foreach-loop is giving the error. — user2947695, Nov 02 '13 at 13:10
The constructor was a part of trying to solve the problem earlier. Removed it now. Is Model.VognItems null? How can I solve it? — user2947695, Nov 02 '13 at 13:12
Where are you creating the `HandlevognViewModel`, I don't see it in your code. Also, which view are you showing? — Henk Mollema, Nov 02 '13 at 13:29
Put breakpoint inside loop and check what exact value gives null reference error, either Model.VognItems or @item.Produkt — LINQ2Vodka, Nov 02 '13 at 13:47
in continue, are you sure this line: VognItems = vogn.GetVognItems() gives items that all have Produkt? — LINQ2Vodka, Nov 02 '13 at 13:48

score 1 · Answer 1 · answered Nov 02 '13 at 13:07

1

in your model, add a private field:

private List<Handlevogn> vognitems = new List<Handlevogn>();
public List<Handlevogn> VognItems { get { return vognitems; } set { vognitems = value; }

VognItems is null, because you haven't instantiated it.

answered Nov 02 '13 at 13:07

Jonesopolis

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I added the fields you suggested to my HandleVognViewModel, but unfortunately it didn't solve the problem. I get the same error message. – user2947695 Nov 02 '13 at 13:24

"Object reference not set to an instance of an object" When adding to shopping cart

1 Answers1