Null reference exception after POST

Question

I have a form, which gets some values from model. Then, in POST the data user entered are handled and user is redirected to another page. However everytime I post the form, I get null-reference exeption. Where do I make a mistake?

None of the other questions asking about this didn´t solve my problem, that´s why I am asking again with my specific code.

The exeptions are at foreach loops - Model.Cart, Model.ShippingOptionsm etc.

@model CheckoutViewModel
@{
ViewBag.Title = "Checkout";
Layout = "~/Views/Shared/_Layout.cshtml";
}

<h2>Checkout</h2>
<table class="table">
    <thead>
        <tr>
            <td>#</td>
            <td>Name</td>
            <td>Quantity</td>
            <td>Price</td>
            <td>Total price</td>
        </tr>
    </thead>
    @foreach (CartItem i in Model.Cart)
    {
        <tr>
            <td>@Html.Action("ProductPosition", "Cart", new { item = i })</td>
            <td>@i.Name</td>
            <td>@i.Quantity</td>
            <td>@i.Price €</td>
            <td>@i.Total €</td>
        </tr>
    }

</table>
<h3>Total: @Html.Action("TotalPrice", "Cart") €</h3>

@using (Html.BeginForm("Checkout", "Cart"))
{
    @Html.AntiForgeryToken()
    <h2>Address</h2>
    <div class="form-group">
        @Html.LabelFor(m => m.Name)
        @Html.TextBoxFor(m => m.Name, new { @class = "form-control" })
        @Html.ValidationMessageFor(m => m.Name)
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.Address)
        @Html.TextBoxFor(m => m.Address, new { @class = "form-control" })
        @Html.ValidationMessageFor(m => m.Address)
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.City)
        @Html.TextBoxFor(m => m.City, new { @class = "form-control" })
        @Html.ValidationMessageFor(m => m.City)
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.PostNumber)
        @Html.TextBoxFor(m => m.PostNumber, new { @class = "form-control" })
        @Html.ValidationMessageFor(m => m.PostNumber)
    </div>
    <div class="form-group">
        @Html.LabelFor(m => m.State)
        @Html.TextBoxFor(m => m.State, new { @class = "form-control" })
        @Html.ValidationMessageFor(m => m.State)
    </div>



    <h2>Shipping</h2>
    foreach (var i in Model.ShippingOptions)
    {
        <div class="radio">
            @Html.RadioButtonFor(m => m.ShippingOption, i.Id) @i.Name - @i.Price €
        </div>
    }
    @Html.ValidationMessageFor(m => m.ShippingOption);

    <h2>Payment</h2>
    foreach (var i in Model.PaymentOptions)
    {
        <div class="radio">
            @Html.RadioButtonFor(m => m.PaymentOption, i.Id) @i.Name
        </div>
    }
    @Html.ValidationMessageFor(m => m.PaymentOption);
    <button type="submit" class="btn btn-primary">Continue</button>
}
@section scripts
{
    @Scripts.Render("~/bundles/jqueryval")
}

Controller:

public ActionResult Checkout()
    {
        if (Session["cart"] == null)
            return RedirectToAction("Index");

        var checkout = new CheckoutViewModel()
        {
            Cart = (List<CartItem>)Session["cart"],
            PaymentOptions = _context.PaymentOptions.ToList(),
            ShippingOptions = _context.ShippingOptions.ToList()
        };


        return View(checkout);
    }

    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Checkout(CheckoutViewModel m)
    {
        if (!ModelState.IsValid)
            return View();

        //TODO: handle data

        return RedirectToAction("OrderSuccess");
    }

You missed `@model CheckoutViewModel` at the top in the view — J Santosh, Aug 08 '16 at 13:10
@J Santosh I have it there, i just missed it when copying. Added it to original post — Marinaro, Aug 08 '16 at 13:22
If `ModelState` is not valid, you return the view, but you have not repopulated the collections for `Cart`, `ShippingOptions` etc, so they are `null` - hence the exception — , Aug 08 '16 at 23:29
You missed var checkout = code in your post method . Write that code in if block of post method — J Santosh, Aug 09 '16 at 03:49

score 0 · Answer 1 · answered Aug 08 '16 at 13:11

0

Add model declaration at the top of the page

@model CheckoutViewModel

answered Aug 08 '16 at 13:11

Mostafiz

7,243
3
28
42

I have it there, i just missed it when copying. Added it to original post – Marinaro Aug 08 '16 at 13:22

Null reference exception after POST

1 Answers1