Pagination

gistfile1.cs

   public class PaginatedList<T> : List<T>
   {
        private int totalItems;
        private int totalPages;

        public int PageIndex { get; private set; }

        public PaginatedList(IQueryable<T> items, int pageIndex, int perPage)
        {
            PageIndex = pageIndex < 0 ? 0 : pageIndex;
            totalItems = items.Count();
            totalPages = (int)Math.Ceiling(totalItems / (double)perPage);
            this.AddRange(items.Skip(PageIndex * perPage).Take(perPage));
        }

        public IEnumerable<int?> EnumeratePages(int leftEdge = 2, int leftCurrent = 2,
                                                int rightCurrent = 5, int rightEdge = 2)
        {
            int last = 0;
            for (int pageNum = 1; pageNum < totalPages + 1; ++pageNum)
            {
                if ((pageNum <= leftEdge) || (pageNum > PageIndex - leftCurrent - 1 && pageNum < PageIndex + rightCurrent) ||
                    (pageNum > totalPages - rightEdge))
                {
                    if (last + 1 != pageNum)
                        yield return null;

                    yield return pageNum;
                    last = pageNum;
                }
            }
        }

        public bool HasNext
        {
            get
            {
                return PageIndex < totalPages - 1;
            }
        }

        public MvcHtmlString Render(HtmlHelper helper)
        {
            StringBuilder builder = new StringBuilder();
            builder.Append(@"<div class=""pagination"">");

            foreach (int? pageNum in EnumeratePages())
            {
                if (pageNum.HasValue)
                {
                    int pageIndex = pageNum.Value - 1;
                    if (pageIndex != PageIndex)
                    {
                        helper.ViewContext.RouteData.Values["page"] = pageNum.Value;
                        builder.Append(helper.RouteLink(pageNum.Value.ToString(), helper.ViewContext.RouteData.Values).ToHtmlString());
                    }
                    else
                    {
                        builder.AppendFormat("<strong>{0}</strong>", pageNum.Value);
                    }
                }
                else
                {
                    builder.Append("<span class=ellipsis>…</span>");
                }
            }

            if (HasNext)
            {
                helper.ViewContext.RouteData.Values["page"] = PageIndex + 2;
                builder.Append(helper.RouteLink("Next", helper.ViewContext.RouteData.Values).ToHtmlString());
            }

            builder.Append("</div>");

            return MvcHtmlString.Create(builder.ToString());
        }
    }