asp.net （c#） MySQL 大数据快速分页

aspx页:
<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True"
OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged" CssClass="b">
<asp:ListItem Value="5">5 per page</asp:ListItem>
<asp:ListItem Selected="True" Value="10">10 per page</asp:ListItem>
<asp:ListItem Value="50">50 per page</asp:ListItem>
</asp:DropDownList> --每页显示条数
<asp:Label ID="lbpageof" runat="server"></asp:Label> --显示方式
<asp:LinkButton ID="lbpre" runat="server" CommandArgument="prev" OnClick="PagerButtonClick">Previous</asp:LinkButton> --前一页
<asp:LinkButton ID="lbnext" runat="server" CommandArgument="next" OnClick="PagerButtonClick">Next</asp:LinkButton> --后一页
<asp:LinkButton ID="lbpre2" runat="server" CommandArgument="prev" OnClick="PagerButtonClick">Previous</asp:LinkButton> --前一页2
<asp:LinkButton ID="lbnext2" runat="server" CommandArgument="next" OnClick="PagerButtonClick">Next</asp:LinkButton> --后一页2
<input id="hid_CurrentIndex"
runat="server" type="hidden" /> --索引数
cs:
hid_CurrentIndex.Value = "0"; 初始化为0
首先给出_sqlStr(sql语句)
DataSet ds;
通过程序得到一个（ds）Dataset
ds = _db.GetDataSet(_sqlStr + " limit " + (Convert.ToInt64(hid_CurrentIndex.Value) * Convert.ToInt64(DropDownList1.SelectedValue)) + "," +
DropDownList1.SelectedValue); --DropDownList1.SelectedValue1的值为每页显示条数
GridView1.PageSize = 10;
GridView1.DataSource = ds.Tables[0].DefaultView;
GridView1.DataBind();
linkbttonenableset()；
private void linkbttonenableset()
{
try
{

double dblTotalRecords = Convert.ToDouble(取得总的记录行数单独写个sql_count);