passing model to action method in form

Question

I have a view which look like this

    @model UI.Models.BidOnAuctionViewModel

<script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script>

@{
    var disableButton = Model.AuctionOpen ? "" : "bid-btn-disabled";         
}

@using (Html.BeginForm("ConfirmBid", "Lot"))
{
    <fieldset>
        @Html.HiddenFor(model => model.AuctionId)

        <p>
            <label >&pound;@Model.NextBidAmount</label>
        </p>
        <p>
            @if (Model.AuctionOpen)
            {
                 <input type="submit" value="Place bid" class="bid-btn @disableButton" />
            }
        </p>
    </fieldset>
}

When I click on the Place bid button, I go to the confirmBid action method

[Authorize]
[HttpPost]
public ActionResult ConfirmBid(BidOnAuctionViewModel model)

The problem is that even though in the view the model was not null, for some reason it is null in this action method. Why is this?

Why you are passing the model in Form? It automatically gets the current model when you post because you have already specified type for view. — Kundan Singh Chouhan, Oct 09 '12 at 17:32
Ok but I tried not to pass the form and although the model wasn't null, certain fields in the model which should have not been null were. — Sachin Kainth, Oct 09 '12 at 17:34
Do you mean to say some of the fields are null not the whole model? — Kundan Singh Chouhan, Oct 09 '12 at 17:37
yes some fields are null when I don't pass the model like I just showed — Sachin Kainth, Oct 09 '12 at 17:38
Some fields become null because you didn't specified anything in to that fields in view. — Kundan Singh Chouhan, Oct 09 '12 at 17:38
but the model that came into that view does contain values for those fields — Sachin Kainth, Oct 09 '12 at 17:41
okay than provide your whole view mark up. Might be there are some duplicate name fields — Kundan Singh Chouhan, Oct 09 '12 at 17:42
Sorry, I didn't mean null I meant 0. The value is a decimal and it is 0 not null — Sachin Kainth, Oct 09 '12 at 17:42

score 1 · Accepted Answer · answered Oct 09 '12 at 17:49

1

After analyzing your code i found the issue. Actually you are just displaying the value of NextBidAmount. And when form get post again the model object lost its value.

To persist its value on post in model just create a hidden field for it as you already done for AuctionId

@Html.HiddenFor(model => model.NextBidAmount)

This will fix your issue.

answered Oct 09 '12 at 17:49

Kundan Singh Chouhan

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Why does this happen. Why do you need to put a hidden field in? – Sachin Kainth Oct 09 '12 at 17:53
Hidden field persist the value of you field on post. Form will post all the input fields to controller and you were not putting it in to any input element. – Kundan Singh Chouhan Oct 09 '12 at 17:57

passing model to action method in form

1 Answers1