Question

I have the following MVC form and controller to upload an image for merchandise with a given id. The id is null when this form is submitted to the controller for some reason. I checked in the rendered HTML and the correct ID is being rendered on the webpage.

The form:

@using(Html.BeginForm(new{id = ViewBag.id})){

<input type="hidden" name="id" id="id" value="@ViewBag.Id"/>

<label for="file">Filename:</label>
<input type="file" name="file" id="file" />
<input type="submit" />
}

And the controller:

[HttpPost]
public ActionResult AddImage(int merchandiseId, HttpPostedFileBase image)
<snip>

Why would submitting this form cause merchandiseId to be null?

Answer 1

Becouse you use wrong names. Change

<input type="hidden" name="id" id="id" value="@ViewBag.Id"/>

to

<input type="hidden" name="merchandiseId" id="id" value="@ViewBag.Id"/>

or

public ActionResult AddImage(int merchandiseId, HttpPostedFileBase image)

to

public ActionResult AddImage(int id, HttpPostedFileBase image)