HomeController.cs file for the JQUERY DATATABLES 1.10+ AND ASP.NET MVC 5 SERVER SIDE INTEGRATION

HomeController.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using MVCDatatableApp.Models;

namespace MVCDatatableApp.Controllers
{
    public class HomeController : Controller
    {
        public ActionResult Index()
        {
            return View();
        }

        public JsonResult DataHandler(DTParameters param)
        {
            try
            {
                var dtsource = new List<Customer>();
                using (dataSetEntities dc = new dataSetEntities())
                {
                    dtsource = dc.Customers.ToList();
                }

                List<String> columnSearch = new List<string>();

                foreach (var col in param.Columns)
                {
                    columnSearch.Add(col.Search.Value);
                }

                List<Customer> data = new ResultSet().GetResult(param.Search.Value, param.SortOrder, param.Start, param.Length, dtsource, columnSearch);
                int count = new ResultSet().Count(param.Search.Value, dtsource, columnSearch);
                DTResult<Customer> result = new DTResult<Customer>
                {
                    draw = param.Draw,
                    data = data,
                    recordsFiltered = count,
                    recordsTotal = count
                };
                return Json(result);
            }
            catch (Exception ex)
            {
                return Json(new { error = ex.Message });
            }
        }
    }
}

There is a minor issue with the recordsFiltered / recordsTotal counters

                draw = param.Draw,
                data = data,
                recordsFiltered = count,
                recordsTotal = count

If recrodsFiltered and recordsTotal are equal, the oLanguage: sInfoFilered text from the DataTable will never show up. I think that recordsTotal should be equal to dtsource.Count() so that you can show something line "Showing 1 to 10 from 128 entries (filtered from 35978 recrods) " so that in all cases you can see how many total records you have, how many match the filter.

                draw = param.Draw,
                data = data,
                recordsFiltered = count,
                recordsTotal = dtsource.Count()