public async Task <ActionResult> Index(string currentFilter, int?page, string searchString = null, string sortOrder = null)
        {
            ViewBag.CurrentSort  = sortOrder;
            ViewBag.NameSortParm = sortOrder == "Name" ? "name_desc" : "Name";
            ViewBag.NameSortParm = sortOrder == "StartTime" ? "startTime_desc" : "StartTime";
            ViewBag.NameSortParm = sortOrder == "EndTime" ? "endTime_desc" : "EndTime";
            if (searchString != null)
            {
                page = 1;
            }
            else
            {
                searchString = currentFilter;
            }
            ViewBag.CurrentFilter             = searchString;
            AssignmentParameters.PageSize     = 5;
            AssignmentParameters.PageNumber   = (page ?? 1);
            AssignmentParameters.SearchString = searchString;
            AssignmentParameters.SortOrder    = sortOrder;
            AssignmentParameters.Paged        = true;

            var assignmentPagedList = await Service.GetAllPagedListAsync(AssignmentParameters);

            var viewModel      = Mapper.Map <IEnumerable <AssignmentIndexViewModel> >(assignmentPagedList);
            var pagedViewModel = new StaticPagedList <AssignmentIndexViewModel>(viewModel, assignmentPagedList.GetMetaData());

            return(View(pagedViewModel));
        }