Get page number from datapager control in asp.net

<asp:DataPager ID="listPager" runat="server"   PagedControlID="lviewEarnSearch" PageSize="10"   OnPreRender="listPager_PreRender" QueryStringField="pageid">
  <Fields>
    <asp:NumericPagerField />
    <asp:NextPreviousPagerField LastPageText=">>>" ShowNextPageButton="false" ShowLastPageButton="True" ShowPreviousPageButton="False" />
  </Fields>
</asp:DataPager>

"QueryStringField" is used for Get Page Number of paging.