[c#] Displaying Total in Footer of GridView and also Add Sum of columns(row vise) in last Column

In my Asp.net App, i have a GridView and i generate the data of column[6] by myself using code behind.

by looking at the code below, i have a footer for my gridview. and the problem is my text for column[6] won't appear if i use footer. If i delete the footertext code, then my text for column[6] is appear. what is the problem? both of the code cant use togather? i already set ShowFooter="True"

protected void Page_Load(object sender, EventArgs e)
{
    for (int i = 0; i < (this.GridView1.Rows.Count); i++)
    {
       this.GridView1.Rows[i].Cells[6].Text = "testing";
       //GridView1.Columns[1].FooterText ="footer 1";
    }
}

.aspx

<asp:GridView ID="GridView1" runat="server" DataSourceID="SqlDataSource1" 
            AutoGenerateColumns="False" DataKeyNames="ID" CellPadding="4" 
            ForeColor="#333333" GridLines="None" ShowFooter="True" 
                    onrowdatabound="GridView1_RowDataBound">
            <RowStyle BackColor="#EFF3FB" />
            <Columns>
                <asp:BoundField DataField="reportDate" HeaderText="Report Date" dataformatstring="{0:dd MMMM yyyy}" SortExpression="reportDate" />
                <asp:BoundField DataField="sponsorBonus" HeaderText="Sponsor Bonus"  dataformatstring="{0:0.00}" SortExpression="sponsorBonus" HtmlEncode="False" />
                <asp:BoundField DataField="pairingBonus" HeaderText="Pairing Bonus" HtmlEncode="False" SortExpression="pairingBonus" dataformatstring="{0:c}" />                                       
                <asp:BoundField DataField="staticBonus" HeaderText="Static Bonus"  SortExpression="staticBonus" />
                <asp:BoundField DataField="leftBonus" HeaderText="Left Bonus"  SortExpression="leftBonus" />
                <asp:BoundField DataField="rightBonus" HeaderText="Right Bonus"  SortExpression="rightBonus" />
                <asp:BoundField HeaderText="Total" SortExpression="total" >
                <ItemStyle Width="100px" />
                </asp:BoundField>
            </Columns>
            <FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
            <PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />
            <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />
            <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
            <EditRowStyle BackColor="#2461BF" />
            <AlternatingRowStyle BackColor="White" />            
        </asp:GridView>

     <asp:TemplateField HeaderText="ExEmp" HeaderStyle-HorizontalAlign="Center" ItemStyle-HorizontalAlign="Center"
                                                                    FooterStyle-BackColor="BurlyWood" FooterStyle-HorizontalAlign="Center">
                                                                    <ItemTemplate>
                                                                        <asp:TextBox ID="txtNoOfExEmp" runat="server" CssClass="form-control input-sm m-bot15"
                                                                            Font-Bold="true" onkeypress="return isNumberKey(event)" Text='<%#Bind("ExEmp") %>'></asp:TextBox>
                                                                    </ItemTemplate>
                                                                    <HeaderStyle HorizontalAlign="Center"></HeaderStyle>
                                                                    <ItemStyle HorizontalAlign="Center" Width="50px" />
                                                                    <FooterTemplate>
                                                                        <asp:Label ID="lblTotNoOfExEmp" Font-Bold="true" runat="server" Text="0" CssClass="form-label"></asp:Label>
                                                                    </FooterTemplate>
                                                                </asp:TemplateField>


 private void TotalExEmpOFMonth()
    {
        Label lbl_TotNoOfExEmp = (Label)GrdPFRecord.FooterRow.FindControl("lblTotNoOfExEmp");
        /*Sum of the  Total Amount Of month*/
        foreach (GridViewRow gvr in GrdPFRecord.Rows)
        {
            TextBox txt_NoOfExEmp = (TextBox)gvr.FindControl("txtNoOfExEmp");
            lbl_TotNoOfExEmp.Text = (Convert.ToDouble(txt_NoOfExEmp.Text) + Convert.ToDouble(lbl_TotNoOfExEmp.Text)).ToString();
            lbl_TotNoOfExEmp.Text = string.Format("{0:F0}", Decimal.Parse(lbl_TotNoOfExEmp.Text));



        }
    }

/*This code will use gridview sum inside data list*/
SumOFdata(grd_DataDetail);

  private void SumOFEPFWages(GridView grd)
    {
        Label lbl_TotAmt = (Label)grd.FooterRow.FindControl("lblTotGrossW");
        /*Sum of the total Amount of the day*/
        foreach (GridViewRow gvr in grd.Rows)
        {
            Label lbl_Amount = (Label)gvr.FindControl("lblGrossS");
            lbl_TotAmt.Text = (Convert.ToDouble(lbl_Amount.Text) + Convert.ToDouble(lbl_TotAmt.Text)).ToString();
        }

    }

This can be achieved through LINQ with grouping, here a list of items pointed as a data source to the actual grid view. Sample pseudo code which could help coding the actual.

var tabelDetails =(from li in dc.My_table
    join m in dc.Table_One on li.ID equals m.ID
    join c in dc.Table_two on li.OtherID equals c.ID
    where //Condition
group new { m, li, c } by new
{
    m.ID,
    m.Name
} into g
select new
{
    g.Key.ID,
    Name = g.Key.FullName,
    sponsorBonus= g.Where(s => s.c.Name == "sponsorBonus").Count(),
    pairingBonus = g.Where(s => s.c.Name == "pairingBonus").Count(),
    staticBonus = g.Where(s => s.c.Name == "staticBonus").Count(),   
    leftBonus = g.Where(s => s.c.Name == "leftBonus").Count(),  
    rightBonus = g.Where(s => s.c.Name == "rightBonus").Count(),  
    Total = g.Count()  //Row wise Total
}).OrderBy(t => t.Name).ToList();

tabelDetails.Insert(tabelDetails.Count(), new  //This data will be the last row of the grid
{
    Name = "Total",  //Column wise total
    sponsorBonus = tabelDetails.Sum(s => s.sponsorBonus),
    pairingBonus = tabelDetails.Sum(s => s.pairingBonus),
    staticBonus = tabelDetails.Sum(s => s.staticBonus),
    leftBonus = tabelDetails.Sum(s => s.leftBonus),
    rightBonus = tabelDetails.Sum(s => s.rightBonus ),
    Total = tabelDetails.Sum(s => s.Total)
});

int total = 0;
protected void gvEmp_RowDataBound(object sender, GridViewRowEventArgs e)
{
if(e.Row.RowType==DataControlRowType.DataRow)
{
total += Convert.ToInt32(DataBinder.Eval(e.Row.DataItem, "Amount"));
}
if(e.Row.RowType==DataControlRowType.Footer)
{
Label lblamount = (Label)e.Row.FindControl("lblTotal");
lblamount.Text = total.ToString();
}
}

protected void gvBill_RowDataBound(object sender, GridViewRowEventArgs e)
    {

        if (e.Row.RowType == DataControlRowType.DataRow)

            Total += Convert.ToDecimal(DataBinder.Eval(e.Row.DataItem, "InvMstAmount"));
        else if (e.Row.RowType == DataControlRowType.Footer)

            e.Row.Cells[7].Text = String.Format("{0:0}", "<b>" + Total + "</b>");
    }