linq分页扩展

原文地址：http://www.cnblogs.com/RainbowInTheSky/p/4590508.html

　　　　 public static List<T> ToPagedList<T>(this IEnumerable<T> allItems, int pageIndex, int pageSize, Expression<Func<T, int>> keySelector)

        {

            var itemList = allItems.Skip(pageSize * (pageIndex - 1)).Take(pageSize).ToList();

            return itemList;

        }

        public static List<T> ToPagedList<T>(this IEnumerable<T> allItems, int pageIndex, int pageSize, Expression<Func<T, bool>> keySelector)

        {

            var itemList = allItems.Skip(pageSize * (pageIndex - 1)).Take(pageSize).ToList();

            return itemList;

        }

        public static List<T> ToPagedList<T>(this IEnumerable<T> allItems, int pageIndex, int pageSize, Expression<Func<T, string>> keySelector)

        {

            var itemList = allItems.Skip(pageSize * (pageIndex - 1)).Take(pageSize).ToList();

            return itemList;

        }

        public static List<T> ToPagedList<T>(this IEnumerable<T> allItems, int pageIndex, int pageSize, Expression<Func<T, DateTime>> keySelector)

        {

            var itemList = allItems.Skip(pageSize * (pageIndex - 1)).Take(pageSize).ToList();

            return itemList;

        }

        public static List<T> ToPagedList<T>(this IQueryable<T> allItems, int pageIndex, int pageSize, Expression<Func<T, int>> keySelector)

        {

            var itemList = allItems.OrderBy(keySelector).Skip(pageSize * (pageIndex - 1)).Take(pageSize).ToList();

            return itemList;

        }

        public static List<T> ToPagedList<T>(this IQueryable<T> allItems, int pageIndex, int pageSize, Expression<Func<T, bool>> keySelector)

        {

            var itemList = allItems.OrderBy(keySelector).Skip(pageSize * (pageIndex - 1)).Take(pageSize).ToList();

            return itemList;

        }

        public static List<T> ToPagedList<T>(this IQueryable<T> allItems, int pageIndex, int pageSize, Expression<Func<T, string>> keySelector)

        {

            var itemList = allItems.OrderBy(keySelector).Skip(pageSize * (pageIndex - 1)).Take(pageSize).ToList();

            return itemList;

        }

        public static List<T> ToPagedList<T>(this IQueryable<T> allItems, int pageIndex, int pageSize, Expression<Func<T, DateTime>> keySelector)

        {

            var itemList = allItems.OrderBy(keySelector).Skip(pageSize * (pageIndex - 1)).Take(pageSize).ToList();

            return itemList;

        }