/// <summary>

       /// 排序

       /// </summary>

       /// <typeparam name="T"></typeparam>

       /// <param name="source"></param>

       /// <param name="sortExpression"></param>

       /// <param name="sortDirection"></param>

       /// <returns></returns>

        public static IQueryable<T> DataSorting<T>(IQueryable<T> source, string sortExpression, string sortDirection)

        {

            string sortingDir = string.Empty;

            if (sortDirection.ToUpper().Trim() == "ASC")

                sortingDir = "OrderBy";

            else if (sortDirection.ToUpper().Trim() == "DESC")

                sortingDir = "OrderByDescending";

            ParameterExpression param = Expression.Parameter(typeof(T), sortExpression);

            PropertyInfo pi = typeof(T).GetProperty(sortExpression);

            Type[] types = new Type[];

            types[] = typeof(T);

            types[] = pi.PropertyType;

            Expression expr = Expression.Call(typeof(Queryable), sortingDir, types, source.Expression, Expression.Lambda(Expression.Property(param, sortExpression), param));

            IQueryable<T> query = source.AsQueryable().Provider.CreateQuery<T>(expr);

            return query;

        }