DataTable dt = GetData();
   int count = dt.Rows.Count;

   DataTable dt_jishu = new DataTable();
   DataTable dt_oushu = new DataTable();
   dt_jishu = dt.Copy();
   dt_oushu = dt.Copy();

 for(int i = 1; i <= count/2; i++)
   dt_jishu.Rows.RemoveAt(i);
 for(int i= 0 ;i <= count/2-1; i++)
   dt_oushu.Rows.RemoveAt(i);

如果有datalist，需要显示这样的格式：
1        a        |       2            b
3        c        |       4            d
6        e        |       6            f
7        g        |       8            h

     this.dl1.DataSource = dt_jishu;
     this.dl1.DataBind();
     this.dl2.DataSource = d;
     this.dl2.DataBind();

使用下面的语句分别作为 dl1、dl2的排序编号：

<%#((System.Web.UI.WebControls.DataListItem)Container).ItemIndex*2+1%>
<%#((System.Web.UI.WebControls.DataListItem)Container).ItemIndex*2+2%>