MVC3 Areas routing conflict - asp.net-mvc-3

Question

Question: i want my route to be like that
/admin/main/category/1 -> 1 == ?page=1
i don't want page=1 to be seen
My Controller
public class MainController : BaseController
{
private const int PageSize = 5; //pager view size
[Inject]
public ICategoryRepository CategoryRepository { get; set; }
public ActionResult Index()
{
return View();
}
public ActionResult Category(int page)
{
//int pageIndex = page.HasValue ? page.Value : 1;
int pageIndex = page != 0 ? page : 1;
return View("Category", CategoryViewModelFactory(pageIndex));
}
/*
*Helper: private instance/static methods
======================================================================*/
private CategoryViewModel CategoryViewModelFactory(int pageIndex) //generate viewmodel category result on pager request
{
return new CategoryViewModel
{
Categories = CategoryRepository.GetActiveCategoriesListDescending().ToPagedList(pageIndex, PageSize)
};
}
}
public class AdminAreaRegistration : AreaRegistration
{
public override string AreaName
{
get
{
return "admin";
}
}
public override void RegisterArea(AreaRegistrationContext context)
{
context.MapRouteLowercase(
"AdminCategoryListView",
"admin/{controller}/{action}/{page}",
new { controller = "Category", action = "Category", page = "1" },
new { id = #"\d+" },
new[] { "WebUI.Areas.Admin.Controllers" }
);
}
}
My Exception:
The parameters dictionary contains a null entry for parameter 'page'
of non-nullable type 'System.Int32' for method
'System.Web.Mvc.ActionResult Category(Int32)' in
'WebUI.Areas.Admin.Controllers.MainController'. An optional parameter
must be a reference type, a nullable type, or be declared as an
optional parameter. Parameter name: parameters
Thank you all in advance.

Answer 1

Make sure that in your Admin area route registration you have defined the {page} route token instead of {id} which is generated by default:
public override void RegisterArea(AreaRegistrationContext context)
{
context.MapRoute(
"Admin_default",
"Admin/{controller}/{action}/{page}",
new { action = "Index", page = UrlParameter.Optional }
);
}
Now when you are generating links make sure you specify this parameter:
#Html.ActionLink(
"go to page 5", // linkText
"category", // actionName
"main", // controllerName
new { area = "admin", page = "5" }, // routeValues
null // htmlAttributes
)
will emit:
go to page 5
and when this url is requested the Category action will be invoked and passed page=5 parameter.