<asp:gridview id="Gridview1" runat="server" autogeneratecolumns="False" allowpaging="True" onpageindexchanging="Gridview1_PageIndexChanging" xmlns:asp="#unknown"></asp:gridview>
static DataTable dt;
Gridview1.DataSource = dt;
Gridview1.DataBind();
protected void Gridview1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
Gridview1.PageIndex = e.NewPageIndex;
Gridview1.DataSource = dt;
Gridview1.Page.DataBind();
}
This will help you properly