Question

I’m new to asp.net mvc. I have index method with parameter id :

 public ActionResult Index(int id)
    {

        var dc = new ServicesDataContext();
        var query = (from m in dc.Mapings
                   where m.CustomerID == id
                    select m);
       // var a = dc.Customers.First(m => m.CustomerId == id);
       // ViewData.Model = a;
       // return View();
        return View(query);
    }

Now when I try to redirect to index from edit i get an error ” The parameters dictionary contains a null entry for parameter ‘id’ of non-nullable type ‘System.Int32’ for method ‘System.Web.Mvc.ActionResult Index(Int32)’ in ‘MVCServices.Controllers.CustomerserviceController’. An optional parameter must be a reference type, a nullable type, or be declared as an optional parameter.

   [HttpPost]
    public ActionResult Edit( FormCollection form)
    {
        var id = Int32.Parse(form["CustomerServiceMappingID"]);

        var datacontext = new ServicesDataContext();
        var serviceToUpdate = datacontext.Mapings.First(m => m.CustomerServiceMappingID == id);
        TryUpdateModel(serviceToUpdate, new string[] { "CustomerID", "ServiceID", "Status" }, form.ToValueProvider());

        if (ModelState.IsValid)
        {
            try
            {
                var qw = (from m in datacontext.Mapings
                          where id == m.CustomerServiceMappingID
                          select m.CustomerID).First();
                datacontext.SubmitChanges();
                //return Redirect("/Customerservice/Index/qw");
                return RedirectToAction("Index", new { qw = qw });
            }
            catch{
                }
        }

        return View(serviceToUpdate);
    }

This is the View:

                 @Html.ActionLink("Back to List", "Index")

The id in the Index method turns out to be the customerid fetched from another controller while id in Edit is from another table.Can you please let me know the mistake I’ve been doing and how to solve it?

Answer 1

Do this in the Edit action:

return RedirectToAction("Index", new { id = qw });