asp.net mvc paging error - asp.net-mvc

Question

I have a pagination problem. I have a Product model, it has a string ProductCategory attribute. One page can take 4 products, whenever it exceeds 4, it points out page 2. The problem is that when I click "Car" category and click page 2, it takes every product, rather than taking only "Car" .
I got the book from the book, ASP.NET MVC 4, published by apress.
Here is my ProductListViewModel:
public class ProductsListViewModel
{
public List<Product> Products { get; set; }
public PagingInfo PagingInfo { get; set; }
public string CurrentCategory { get; set; }
}
Here is my ProductController's List Action: When I debug the application, at the click at page 2, category parameter is null.
public ViewResult List(string category, int page = 1)
{
ProductsListViewModel model = new ProductsListViewModel
{
Products = repository.Products
.Where(p => category == null || p.ProductCategory.Equals(category))
.OrderBy(p => p.ProductID)
.Skip((page - 1) * PageSize).Take(PageSize).ToList(),
PagingInfo = new PagingInfo
{
CurrentPage = page,
ItemsPerPage = PageSize,
TotalItems = category == null ?
repository.Products.Count() :
repository.Products.Where(e => e.ProductCategory == category).Count()
}
};
model.CurrentCategory = category;
return View(model);
}
Here is my List View:
#model SportsStore.WebUI.Models.ProductsListViewModel
#{
ViewBag.Title = "Products";
}
#foreach (var p in Model.Products)
{
<div class="item">
#Html.Partial("ProductSummary", p)
</div>
}
<div class="pager">
#Html.PageLinks(Model.PagingInfo, x => Url.Action("List", new { page = x, ProductCategory = Model.CurrentCategory }))
ProductSummary is a partial view that views the product. Pagelinks is a extention methods:
public static MvcHtmlString PageLinks(this HtmlHelper html, PagingInfo pagingInfo,
Func<int, string> pageUrl)
{
StringBuilder result = new StringBuilder();
for (int i = 1; i <= pagingInfo.TotalPages; i++)
{
TagBuilder tag = new TagBuilder("a"); // Construct an <a> tag
tag.MergeAttribute("href", pageUrl(i));
tag.InnerHtml = i.ToString();
if (i == pagingInfo.CurrentPage)
tag.AddCssClass("selected");
result.Append(tag.ToString());
}
return MvcHtmlString.Create(result.ToString());
}
As pictured above, when I click page 2, it gets every product, rather than car. How can I solve it?
Thanks in advance.
NOTE: Routes has been added below:
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
routes.MapRoute(null,
"",
new
{
controller = "Product",
action = "List",
category = (string)null,
page = 1
}
);
/*
*http://localhost:56701/?page=2 olmasındansa http://localhost:56701/Page4 olmasını sağlayan kod parçacığı.
*
*/
routes.MapRoute(null,
"Page{page}",
new { controller = "Product", action = "List", category = (string)null },
new { page = #"\d+" }
);
routes.MapRoute(null,
"{category}",
new { controller = "Product", action = "List", page = 1 }
);
routes.MapRoute(null,
"{category}/Page{page}",
new { controller = "Product", action = "List" },
new { page = #"\d+" }
);
routes.MapRoute(null, "{controller}/{action}");
}
}
NOTE 2:
Here is the result when I click page 2 of the Car category:
As you see below, at the page 2, every car items exist. (Blue rectangle). But I do no want to see page 3 and 4 at the bottom of the page (Red rectangle).
Thanks in advance.

Answer 1

The solution has implemented in the book, and it seems it has been escaped from my attention.
Two revisions should be made in the source code, one in List.cshtml :
<div class="pager">
#Html.PageLinks(Model.PagingInfo, x => Url.Action("List", new { page = x, category = Model.CurrentCategory }))
Another is in the List action of the ProductController:
public ViewResult List(string category, int page = 1)
{
ProductsListViewModel viewModel = new ProductsListViewModel
{
Products = repository.Products
.Where(p => category == null || p.ProductCategory == category)
.OrderBy(p => p.ProductID)
.Skip((page - 1) * PageSize)
.Take(PageSize).ToList(),
PagingInfo = new PagingInfo
{
CurrentPage = page,
ItemsPerPage = PageSize,
**TotalItems = category == null ?
repository.Products.Count() :
repository.Products.Where(e => e.ProductCategory == category).Count()**
},
CurrentCategory = category
};
return View(viewModel);
}
TotalItems attribute shall be updated as mentioned above.