Question

I want to do autopostback to dropdownlist.
My form on view:

@using (Html.BeginForm("Index", "Model", FormMethod.Post))
{
            @(Html.Telerik().DropDownList()
                .Name("ddlBrands")
                .BindTo((IEnumerable<SelectListItem>)ViewData["brands"])
                .ClientEvents(events => events
                                  .OnChange("onDropDownListChange")
                )
            )
            <input type="submit" value="OK" />

    <table style="margin:15px; margin-left:0px;">
        @foreach (var item in Model) {
            <tr>
                <td>
                    @Html.DisplayFor(modelItem => item.FullModel)
                </td>
                <td>
                    @Html.ActionLink("Edit", "Edit", new { id=item.ModelID }) |
                    @Html.ActionLink("Delete", "Delete", new { id=item.ModelID })
                </td>
            </tr>
        }
    </table>
}

and javascript:

<script type="text/javascript">
    function onDropDownListChange(e) {
        SimpleAjaxRequest('/Model/Index', e.value);
    }

    function SimpleAjaxRequest(url, requestData) {
        return $.ajax(
        {
            type: 'POST',
            url: url,
            async: true,
            data: { ddlBrands: requestData },
            dataType: "json",
            traditional: true
        });
    }
</script>

I send Post data via Ajax from Index view to server and after manipulation data I need update data on my form. how I can do it? I’m try redirect to POST action

[HttpPost]
        public ActionResult Index(string ddlBrands)
        {
            SetBrandItems();
            return RedirectToAction("Index", "Model", new {ddlBrands = ddlBrands});
        }

after calling GET action

 public ActionResult Index(int? ddlBrands)
    {
        SetBrandItems();
        List<Model> m = dm.GetModelsByBrandId(ddlBrands).ToList();
        return View(m);
    }

but my page not refresh and url not change and data not updating…
anybody can help me?

Answer 1

The DropDownList change event is ajax operaiton. I think you can not redirect in server-side. But you can add a rediect in the ajax callback.

eg:

 function SimpleAjaxRequest(url, requestData) {
    return $.ajax(
    {
        type: 'POST',
        url: url,
        async: true,
        data: { ddlBrands: requestData },
        dataType: "json",
        traditional: true,
        success: function() {
            //callback redirect 
            location.href = '/Model/Index';
        }
    });
}

    [HttpPost]
    public ActionResult Index(string ddlBrands)
    {
        SetBrandItems();
        return Json(null, JsonRequestBehavior.AllowGet);
    }