Html.TextBoxFor not using value of new Model object

I am working on my first MVC Webapplication (using Razor and C#) and I have run across a strange behaviour.

I am editing a "line" of data and using ajax calls to submit and redisplay data. Everything works fine as far as changing existing data and storing it goes. Also if I just redisplay the "line" that was submitted no problems.

However, I want to display a "new" line with some of the values from the old line retained and the rest blanked out.

However, when I submit the new line object to the Partial View, the "blanked" out values aren't being picked up by the @Html.... helpers. But if I display the property of the Model directly it has the correct (blank) value.

Here are the relevant sections of my code: Controller Method: [HttpPost] public ActionResult EditLineForm(SkuRequestLine ln) { SkuRequestLine newline = null;

        try
        {
            if (ln.Store(true))
            {
                ViewData["prodcatdesc"] = DataConnection.GetProductCategory(ln.Category).description;
                newline = new SkuRequestLine();
                newline.Copy(ln);
                newline.Line = DataConnection.NextSkuRequestLineNumber(ln.Request);
                newline.Comments = "";
                newline.Description = "";
                newline.Vendorsku = "";
                return PartialView("EditLineForm", newline);  // this line is being executed.
            }
            else
            {
                return PartialView("EditLineForm", ln);
            }
        }
        catch (Exception ex)
        {
            List<string> msgs = new List<string>();
            while (ex != null)
            {
                msgs.Add(ex.Message);
                ex = ex.InnerException;                
            }
            return PartialView("EditLineForm", ln);
        }
    }

Razor Code:

@model Sku_Management.Models.SkuRequestLine

@using (Ajax.BeginForm("EditLineForm", "SkuRequest", new AjaxOptions { OnSuccess = "UpdateLineList" }))
{
.
.
.
<tr>
    <td>
        <span class="editor-label">
       开发者_C百科     @Html.LabelFor(model => model.Description)
        </span>
    </td>
    <td colspan="5">
        <span class="editor-field">
            @Html.TextBoxFor(model => model.Description, new { @class = "fortywide" })  // Displays the Description from the edited Line passed in.  Not what what Model.Description is.
            @Html.ValidationMessageFor(model => model.Description)
        </span>
        <span>|@Model.Description|</span>  // Displays "||" which is what it should be since Model.Description is blank.
    </td>
</tr>

The only thing I can think of is that model => model.Description is using a cached version of the Model not the new Model passed into the PartialView call.

I have spent the day searching for anything even similar on the web but I can't find anything that even begins to describe this behavior.

Has anyone else encountered this and knows what I am dong wrong?

Thanks

This is because the HTMLHelpers look to the ModelState for values before using the Model.

You'll have to clear the ModelState entries to get this to work.