Calculate Total and Grand Total with additional service like in Restaurant billing in ASP.Net GridView using jQuery

Hi sat,

I have created a sample which full fill your requirement instead of binding textbox you need to bind label 

HTML

<div align="center">
    Quantity:-
    <asp:TextBox ID="lblQuantity" Text="0" OnTextChanged="ValueChange" AutoPostBack="true"
        runat="server" />
    <br />
    <asp:GridView ID="GridView1" runat="server" OnRowDataBound="GridView1_DataBound"
        AutoGenerateColumns="false" ShowFooter="true">
        <Columns>
            <asp:BoundField DataField="Id" HeaderText="Id" />
            <asp:BoundField DataField="Name" HeaderText="Name" />
            <asp:BoundField DataField="HourlyPrice" HeaderText="HourlyPrice" />
            <asp:BoundField HeaderText="Qty" />
            <asp:BoundField HeaderText="Sub-Total" />
        </Columns>
    </asp:GridView>
    <br />
    <asp:GridView ID="GridView2" runat="server" AutoGenerateColumns="false">
        <Columns>
            <asp:TemplateField>
                <ItemTemplate>
                    <asp:CheckBox ID="cbAdditional" runat="server" OnCheckedChanged="CheckedItem" AutoPostBack="true" />
                </ItemTemplate>
            </asp:TemplateField>
            <asp:BoundField DataField="Id" HeaderText="Id" />
            <asp:BoundField DataField="Services" HeaderText="Services" />
            <asp:BoundField DataField="Rate" HeaderText="Rate" />
        </Columns>
    </asp:GridView>
    <br />
    Grand Total=
    <asp:Label ID="lblGrandTotal" runat="server" />
</div>

C#

decimal total = 0;
decimal grandTotal = 0;
protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        BindGrid();
    }
    lblGrandTotal.Text = grandTotal.ToString();
}

private void BindGrid()
{
    DataTable dt = new DataTable();
    dt.Columns.AddRange(new DataColumn[] { new DataColumn("Id"), new DataColumn("Name"), new DataColumn("HourlyPrice") });
    dt.Rows.Add(1, "Derek Tsong", 221);
    dt.Rows.Add(2, "Dolma Mari", 195);
    dt.Rows.Add(3, "Ernet Toko", 251);
    dt.Rows.Add(4, "Pelermo Ivy", 350);
    dt.Rows.Add(5, "Sunil Verma", 290);
    dt.Rows.Add(6, "Lavon Tyagi", 150);
    GridView1.DataSource = dt;
    GridView1.DataBind();

    DataTable dt1 = new DataTable();
    dt1.Columns.AddRange(new DataColumn[] { new DataColumn("Id"), new DataColumn("Services"), new DataColumn("Rate") });
    dt1.Rows.Add(1, "LOC123", 25);
    dt1.Rows.Add(2, "LOC456", 50);
    dt1.Rows.Add(3, "LOC789", 75);
    GridView2.DataSource = dt1;
    GridView2.DataBind();
}

protected void ValueChange(object sender, EventArgs e)
{
    BindGrid();
}

protected void GridView1_DataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        e.Row.Cells[3].Text = lblQuantity.Text;
        e.Row.Cells[4].Text = (Convert.ToInt32(lblQuantity.Text) * Convert.ToInt32(e.Row.Cells[2].Text)).ToString();
        total = total + Convert.ToDecimal(e.Row.Cells[4].Text);
    }
    if (e.Row.RowType == DataControlRowType.Footer)
    {
        e.Row.Cells[3].Text = "Total";
        e.Row.Cells[3].HorizontalAlign = HorizontalAlign.Right;
        e.Row.Cells[4].Text = total.ToString("N2");
        lblGrandTotal.Text = e.Row.Cells[4].Text;
    }
}

protected void CheckedItem(object sender, EventArgs e)
{
    foreach (GridViewRow row in GridView2.Rows)
    {
        CheckBox cb = (CheckBox)row.FindControl("cbAdditional");
        if (cb.Checked)
        {
            grandTotal = grandTotal + Convert.ToDecimal(row.Cells[3].Text);
        }
    }
    if (grandTotal > 0)
    {
        lblGrandTotal.Text = (grandTotal + Convert.ToDecimal(GridView1.FooterRow.Cells[4].Text)).ToString();
    }
    else
    {
        lblGrandTotal.Text = GridView1.FooterRow.Cells[4].Text.ToString();
    }
}

ScreenShot