inconvenient when editing models

Question

I have a problem trying to edit. I work with Areas for better management the application.The problem is in the areas called "Administrator".

Next is the controller code (OfficeControlle), I use a session variable has been previously created and functions to edit the model data I get.

public ActionResult Edit()
        {
            decimal id;
            id = (decimal)Session["consul"];
            CAMPUS_UNIVERSITY campus_university = db. CAMPUS_UNIVERSITY.Single(s => s.Idoffice == id);
            ViewData.Model = db.OFFICE.Single(c => c.Idoffice == id);
            ViewBag.University = db.UNIVERSITY.Single(u => u.IdUniversity == campus_university.IdUniversity);
            ViewBag.campus = db.CITY_CAMPUS.Single(u => u.IdCity == campus_university.Idcitycampus);
            return View(sede_universidad);
        }

         [HttpPost]
        public ActionResult Edit(CAMPUS_UNIVERSITY campus_university, OFFICE office)
        {
            if (ModelState.IsValid)
            {
                db.CAMPUS_UNIVERSITY.Attach(campus_university);
                db.ObjectStateManager.ChangeObjectState(campus_university, EntityState.Modified);
                db.SaveChanges();

                db. OFFICE.Attach(office);
                db.ObjectStateManager.ChangeObjectState(office, EntityState.Modified);
                db.SaveChanges();

                return RedirectToAction("Index");
            }
            ViewBag.IdCitycampus = new SelectList(db.CITY_CAMPUS, "IdCity", "Name", campus_university.IdCitycampus);
            ViewBag.IdConsultorio = new SelectList(db.OFFICE, "Idoffice", "addressoffice", campus_university.Idoffice);
            ViewBag.IdUniversidad = new SelectList(db.UNIVERSITY, "IdUniversity", "Name", campus_university.IdUniversity);
            return View(campus_university);
        }

Next is the view code

@model RolMVC3.Models.CAMPUS_UNIVERSITY

@{
    ViewBag.Title = "Edit"; 
}

<h2>edit</h2>

<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>

@using (Html.BeginForm()) {
    @Html.ValidationSummary(true)

    <h2> @ViewBag.University.Name - @ViewBag.Campus.Name </h2>

    <fieldset>
        <legend>OFFICE</legend>

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

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

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

        <div class="editor-label">
            @Html.LabelFor(model => model.addresscampus)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.addresscampus)
            @Html.ValidationMessageFor(model => model.addresscampus)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.phonecampus)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.phonecampus)
            @Html.ValidationMessageFor(model => model.phonecampus)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.emailcampus)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.emailcampus)
            @Html.ValidationMessageFor(model => model.emailcampus)
        </div>

        <fieldset>
        <legend>OTHER DATE</legend>
        @Html.Partial("_office", Model.OFFICE)
        </fieldset>

        <p>
            <input type="submit" value="Save" />
        </p>
    </fieldset>
}

<div>
    @Html.ActionLink("back", "Index")
</div>

The problem appears when I press the "Save" button, get the following error:

The parameters dictionary contains a null entry for parameter 'Id' of non-nullable type ''System.Decimal' ' for method ''System.Web.Mvc.ActionResult Index(System.Decimal)' in ''RolMVC3.Areas.Administrator.Controllers.OfficeController''

Answer 1

I'm assuming that your Index action method looks something like this (please correct me if I am wrong):

public ActionResult Index(decimal id)
{
     // Your method's code
}

So where you do return RedirectToAction("Index"); you are trying to redirect to an action method that takes no parameters. But in this case there is an action method that requires a parameter, namely id. So when redirecting you need to change your code and supply this id parameter.

This is what you could do:

return RedirectToAction("Index", new { id = /* put your id here */ });

Answer 2

When you are redirecting here:

return RedirectToAction("Index");

make sure that you pass the id in the query string as it looks like your Index action requires it as parameter:

return RedirectToAction("Index", new { id = campus_university.IdUniversity });