DataTable 中的查询、排序及分页(c#)

public class GetDataTable
        {
            /// <summary>
            /// 对sourceDt进行排序，并且可以自由设置显示的条数
            /// --select top (num) from sourceDt order by strSort
            /// </summary>
            /// <param name="sourceDt">原DataTable</param>
            /// <param name="strSort">排序的字段，不用加order by (如: name desc 或 name desc,datecreated desc)</param>
            /// <param name="topNum">显示的数量（为0 是显示全部）</param>
            /// <returns>new DataTable</returns>
            public static DataTable SortTop(DataTable sourceDt, string strSort, int topNum)
            {
                DataTable dt = sourceDt.Clone();

                int totalCount = sourceDt.Rows.Count;
                if (totalCount > 0)
                {
                    DataView dv = sourceDt.DefaultView;
                    dv.Sort = strSort;

                    //计算要显示的条数
                    int count = topNum > 0 ? (topNum > totalCount ? totalCount : topNum) : totalCount;
                    for (int i = 0; i < count; i++)
                    {
                        dt.ImportRow(dv[i].Row);
                    }
                }
                return dt;
            }

            /// <summary>
            /// 对sourceDt进行查询和排序，并且可以自由设置显示的条数
            /// --select top (count) from sourceDt where strSelect order by strSort
            /// </summary>
            /// <param name="sourceDt">原DataTable</param>
            /// <param name="strSelect">查询条件(如:name='me')</param>
            /// <param name="strSort">排序字段，不用加order by (如: name desc 或 name desc,datecreated desc)</param>
            /// <param name="count">显示的数量（为0 是显示全部）</param>
            /// <returns>new DataTable</returns>
            public static DataTable SelectTop(DataTable sourceDt, string strSelect, string strSort, int count)
            {
                DataTable dt = sourceDt.Clone();
                bool noSort = string.IsNullOrEmpty(strSort);
                DataRow[] dr = noSort ? sourceDt.Select(strSelect) : sourceDt.Select(strSelect, strSort);
                foreach (DataRow row in dr)
                {
                    dt.Rows.Add(row.ItemArray);
                }

                int dtCount = dt.Rows.Count;
                if (dtCount > 0)
                {
                    //计算要显示的条数
                    int num = count > 0 ? (count > dtCount ? dtCount : count) : dtCount;
                    DataView dv = dt.DefaultView;

                    if (!noSort)
                    {
                        dv.Sort = strSort;
                    }

                    for (int i = 0; i < num; i++)
                    {
                        dt.ImportRow(dv[i].Row);
                    }
                }
                return dt;
            }

            /// <summary>
            /// DateTable的分页操作
            /// </summary>
            /// <param name="dt">要进行分页的DataTable</param>
            /// <param name="currentPageIndex">当前页数</param>
            /// <param name="pageSize">一页显示的条数</param>
            /// <returns>第pageIndex页的数据</returns>
            public static DataTable SetPage(DataTable dt, int currentPageIndex, int pageSize)
            {
                if (currentPageIndex == 0)
                {
                    return dt;
                }

                DataTable newdt = dt.Clone();

                int rowbegin = (currentPageIndex - 1) * pageSize;//当前页的第一条数据在dt中的位置
                int rowend = currentPageIndex * pageSize;//当前页的最后一条数据在dt中的位置

                if (rowbegin >= dt.Rows.Count)
                {
                    return newdt;
                }

                if (rowend > dt.Rows.Count)
                {
                    rowend = dt.Rows.Count;
                }

                DataView dv = dt.DefaultView;
                for (int i = rowbegin; i <= rowend - 1; i++)
                {
                    newdt.ImportRow(dv[i].Row);
                }

                return newdt;
            }

            /// <summary>
            /// 返回分页的页数
            /// </summary>
            /// <param name="count">总条数</param>
            /// <param name="pageye">每页显示多少条</param>
            /// <returns>如果 结尾为0：则返回1</returns>
            public static int PageCount(int count, int pageye)
            {
                int page = 0;
                int sesepage = pageye;
                if (count % sesepage == 0) { page = count / sesepage; }
                else { page = (count / sesepage) + 1; }
                if (page == 0) { page += 1; }
                return page;
            }
        }