/// <summary>
        /// 删除排序条件
        /// </summary>
        /// <param name="index"></param>
        public void Remove(int index)
        {
            #region
            if (index > Count - 1 || index < 0)
            {
                ExtConsole.WriteWithColor("删除排序时,索引出错!");
                return;
            }
            List.RemoveAt(index);

            #endregion
        }
        /// <summary>
        /// 增加排序条件(可以改进查找匹配算法?)
        /// </summary>
        /// <param name="sqlExpression"></param>
        public void Add(PageSort pagesort)
        {
            #region

            for (int i = 0; i < this.Count; i++)
            {
                if (pagesort._FieldName
                    == ((PageSort)List[i])._FieldName)
                {
                    ExtConsole.WriteWithColor("不能重复添加排序字段!");
                    return;
                }
            }
            List.Add(pagesort);
            #endregion
        }