Lambda动态排序通用方法

using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Text;
using System.Threading.Tasks;

namespace DataSort
{
    public class DataHelper
    {
        public static IQueryable<T> Sort<T>(IQueryable<T> queryable, string sort, string order)
        {
            if (string.IsNullOrWhiteSpace(sort))
            {
                return queryable;
            }
            var sortExpression = Expression.Parameter(queryable.ElementType);
            var selector = Expression.Lambda(Expression.PropertyOrField(sortExpression, sort), sortExpression);
            if (order.ToLower() == "asc")
            {
                return (IQueryable<T>)queryable.Provider.CreateQuery(Expression.Call(typeof(Queryable), "OrderBy", new Type[] { queryable.ElementType, selector.Body.Type }, queryable.Expression, selector));
            }
            else if (order.ToLower() == "desc")
            {

                return (IQueryable<T>)queryable.Provider.CreateQuery(Expression.Call(typeof(Queryable), "OrderByDescending", new Type[] { queryable.ElementType, selector.Body.Type }, queryable.Expression, selector));
            }
            return queryable;
        }
    }
}