Copy (Add) Rows from GridView to DataTable in ASP.Net

HTML

<asp:GridView ID="GridView1" HeaderStyle-BackColor="#3AC0F2" HeaderStyle-ForeColor="White"
        runat="server" AutoGenerateColumns="false">
        <Columns>
            <asp:BoundField DataField="Id" HeaderText="Id" ItemStyle-Width="30" />
            <asp:BoundField DataField="Name" HeaderText="Name" ItemStyle-Width="150" />
            <asp:BoundField DataField="Country" HeaderText="Country" ItemStyle-Width="150" />
        </Columns>
    </asp:GridView>
    <asp:Button runat="server" ID="btnExportGridview" OnClick="ExportGridview" Text="Gridview to Datatable" />

CODE

protected void ExportGridview(object sender, EventArgs e)
    {
        DataSet ds = new DataSet();
        ds.Tables.Add();
        ds.Tables[0].Columns.AddRange(new DataColumn[3] { new DataColumn("Id", typeof(int)), 
                            new DataColumn("Name", typeof(string)), 
                            new DataColumn("Country",typeof(string)) });

        foreach (GridViewRow row in GridView1.Rows)
        {
            ds.Tables[0].Rows.Add(row.Cells[0].Text, row.Cells[1].Text);
        }
    }