asp.net mvc 3 - ModelState.AddModelError is not being displayed inside my view

Question

I have the following view,, which create 10 ajax.beginform ,, But the problem that i am facing is that incase an error occurs during the creation of the object then the ModelState.AddModelError will not be shown on the view although i have set the @Html.ValidationSummary(true) The view looks as follow

@model Medical.Models.VisitLabResult

@for (int item = 0; item < 10; item++)
{
    <tr id = @item>
    @using (Ajax.BeginForm("CreateAll", "VisitLabResult", new AjaxOptions
    {
        HttpMethod = "Post",
        UpdateTargetId = item.ToString() + "td",
        InsertionMode = InsertionMode.Replace,
        LoadingElementId = "progress2",
        OnSuccess = string.Format(
            "disableform({0})",
            Json.Encode(item)),
    }))
    {  
        @Html.ValidationSummary(true)

        @Html.AntiForgeryToken()
        <td>
            @Html.DropDownList("LabTestID", String.Empty)
            @Html.ValidationMessageFor(model => model.LabTestID)
        </td>
        <td>
            @Html.EditorFor(model => model.Result)
            @Html.ValidationMessageFor(model => model.Result)
        </td>

        <td>
            @Html.EditorFor(model => model.DateTaken)
            @Html.ValidationMessageFor(model => model.DateTaken)
        </td>

        <td>
            @Html.EditorFor(model => model.Comment)
            @Html.ValidationMessageFor(model => model.Comment)
        </td>

        <td>
            <input type="submit" value="Create" />
        </td>

        <td id = @(item.ToString() + "td")>
        </td>
    }
    </tr>
    }
</table>

And my action method which defines the ModelState.AddModelError looks as follow:-

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult CreateAll(VisitLabResult vlr, int visitid = 28)
{
    try
    {
        if (ModelState.IsValid)
        {
            var v = repository.GetVisit(visitid);
            if (!(v.EligableToStart(User.Identity.Name))){ 
                return View("NotFound"); 
            }
            vlr.VisitID = visitid;
            repository.AddVisitLabResult(vlr);
            repository.Save();

            return Content("Addedd Succsfully");
        }
    }
    catch (DbUpdateException)
    {
        JsonRequestBehavior.AllowGet);
        ModelState.AddModelError(string.Empty, "The Same test Type might have been already created,, go back to the Visit page to see the avilalbe Lab Tests");
    }
}

So how i can show the ModelState.AddModelError on my view.

Answer 1

I would urge you to change your try{ } catch(){ }

And first check if there exists a visit for the given id and if so simply returns the model with the added model error

    if (visitExists)
    {
         ModelState.AddModelError("CustomError", "The Same test Type might have been already created,, go back to the Visit page to see the avilalbe Lab Tests");
         return View(vlr);    
    }
    //Other code here

Change your AddModelError To

ModelState.AddModelError("CustomError", "The Same test Type might have been already created,, go back to the Visit page to see the avilalbe Lab Tests");

And in your view simply add a

@Html.ValidationMessage("CustomError")

Then when you return your model the error will be shown where you have placed the @Html.ValidationMessage ...