Paging issue in ASP.Net Mvc Application - asp.net-mvc

Question

I am developing an MVC application in which I use a DropdownList to select "vendor". When I select a vendor from the dropdown then the view shows products related to the selected vendor.
I use paging to display multiple pages of particular vendor's products.
My issue is when I select a vendor from dropdown, at change event it displays products on all pages properly. If I select 2nd page it shows products from 2nd page. But next time if I select another vendor from dropdown, it shows 2nd page of selected vendor. But what I want is to display first page of selected vendor initially.
Controller code as below
public ActionResult Index(int? page ,int VendorId = 0)
{
var pageNumber = (page ?? 1);
var pagesize = 2;
if (VendorId == 0)
{
VendorId = Convert.ToInt32(Session["InventoryVendorId"]);
}
VendorService vendorService = new VendorService();
SelectList SelectList = new SelectList(vendorService.GetAll().OrderBy(t => t.Name), "Id", "Name", VendorId);
ViewData["list"] = SelectList;
int id = Convert.ToInt32(Session["loggedEmpId"]);
CommonService.SetEmployeeId(id);
if (VendorId != 0)
{
Session["InventoryVendorId"] = VendorId;
ProductService ProductService = new ProductService();
var productList = ProductService.GetProductInventory().Where(x=>x.VendorId == VendorId);
return View(productList.ToPagedList(pageNumber, pagesize));
}
else
{
return View();
}
}
code for view as below
#model PagedList.IPagedList<StockWatch.DTO.ProductDTO>
#using PagedList.Mvc;
#using System.Web.UI.WebControls
#{
ViewBag.Title = "Index";
int VendorId = Convert.ToInt32(Session["InventoryVendorId"]);
}
<link href="~/Content/PagedList.css" rel="stylesheet" />
<div class="row-fluid">
<div id="vendorDropdownDiv4" class="span12 " style="margin-left:0px;margin-top:10px;">
<div class="span6" >
<div class="span4" style="margin-left:1px;" >
<label >Vendor</label>
</div>
<div class="span6" >
#Html.DropDownList("VendorId", ViewData["list"] as SelectList, "-- Select vendor --", new { #id = "vendorIdforInventory", #name = "VendorId" })
</div>
</div>
<div class="span3" style="text-align:right">
#* <input class="btn btn-primary" type="submit" value="Load" id="create"/>*#
#*<input class="btn btn-default" value="Cancel" style="width:45px;" onclick="window.location.href='#Url.Action("index") '"/>*#
</div>
</div>
</div>
<div id="Newindexview"></div>
#if(Model != null)
{
</div>
<div class="span12" style="margin-left:0px;">
<table>
<thead>
<tr >
<th style="width:250px;" >Product Name
</th>
<th style="width:180px; text-align:left;" >Product Code
</th>
<th style="border-right: solid #e8eef4 thick; width: 0px; text-align:right;">Avg. Weight
</th>
#{
foreach (var location in ViewBag.loc)
{
<th style="width:10px;text-align:right;">#location.Name</th>
}
}
</tr>
</thead>
<tbody>
#foreach (var p in Model)
{
<tr>
<td style="width:250px;">
#p.Name
</td>
<td style="width:180px;text-align:left;">
#p.ProductCode
</td>
<td style="border-right: solid #e8eef4 thick; width: 15px; text-align:right">
#p.AvgWeight
</td>
#foreach (var location in ViewBag.loc)
{
flag = false;
if(p.Inventory != null)
{
foreach (var loc in p.Inventory)
{
if (location.Name == loc.LocationName)
{
<td style="width:10px; text-align:right;">#loc.Quantity</td>
flag = true;
}
}
}
if (flag == false)
{
<td style="width:10px; text-align:right;">0</td>
}
}
</tr>
}
</tbody>
</table>
</div>
<div class="span12" style="margin-left:0px;">
<div class="span6" style="margin-left:0px;">
#Html.PagedListPager(Model, page => Url.Action("Index", new {page ,searchContent=searchcontent}))
</div>
</div>
</div>
}
and jquery code as below
$("#vendorIdforInventory").change(function () {
var vendorid = $('#vendorIdforInventory').val();
$.ajax({
url: '#Url.Action("Index", "Inventory")',
data: {
VendorId: vendorid
},
type: "POST",
success: function (data) {
location.reload();
$('#modeldiv1').empty();
$('#vendorDropdownDiv4').hide();
$('#Newindexview').html("");
$('#Newindexview').html(data);
}
});
});
How to solve this paging issue?

Answer 1

You need to pass the currentFilter from your view back into your controller (which you have with VendorID), and set the page accordingly. Details are in the ASP.NET tutorial on paging at http://www.asp.net/mvc/tutorials/getting-started-with-ef-using-mvc/sorting-filtering-and-paging-with-the-entity-framework-in-an-asp-net-mvc-application.
Look at how they've implemented filtering using the searchString and currentFilter variable, that's what will make sure that when a new string is entered (or selected from a drop down list in your case) that the paging responds accordingly.
Specifically, this is what I think you're missing in your code
if (searchString != null)
{
page = 1;
}
else
{
searchString = currentFilter;
}
...
int pageNumber = (page ?? 1);