ASP.NET Gridview分页问题

<asp:GridView ID="GridView1" runat="server" AllowPaging="True" PageSize="10" OnPageIndexChanging="GridView1_PageIndexChanging">
</asp:GridView>
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ConnectionString %>" SelectCommand="SELECT * FROM [TableName]"></asp:SqlDataSource>
<asp:DataPager ID="DataPager1" runat="server" PagedControlID="GridView1" PageSize="10">
   <Fields>
        <asp:NumericPagerField ButtonType="Link" />
    </Fields>
</asp:DataPager>

protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
    GridView1.PageIndex = e.NewPageIndex;
    GridView1.DataSource = SqlDataSource1;
    GridView1.DataBind();
}