Linq分页

 1   public IQueryable<UserInfo> LoadPageuserInfos<S>(int pageSize, int pageIndex, out int total,
 2            Func<UserInfo, bool> wherelambda, Func<UserInfo, S> orderbyLambda, bool isasc)
 3        {
 4            total = db.UserInfo.Where(wherelambda).Count();
 5 
 6            if (isasc)
 7            {
 8                return db.UserInfo.Where(wherelambda).OrderBy<UserInfo, S>(orderbyLambda)  //OrderBy 看定义；<UserInfo, S> ，UserInfo 可以根据
 9              .Skip(pageSize * (pageIndex - 1))
10              .Take(pageSize).AsQueryable();
11            }
12            else
13            {
14                return db.UserInfo.Where(wherelambda).OrderByDescending<UserInfo, S>(orderbyLambda)
15              .Skip(pageSize * (pageIndex - 1))
16              .Take(pageSize).AsQueryable();
17            }
18        }

 public static IOrderedEnumerable<TSource> OrderBy<TSource, TKey>(this IEnumerable<TSource> source, Func<TSource, TKey> keySelector) {
            return new OrderedEnumerable<TSource, TKey>(source, keySelector, null, false);
        }