ขอโค้ด C# และ asp ในการคำนวณ DataGridView แบบ column

protected void dgv_Matdet_RowDataBound(object sender, GridViewRowEventArgs e)
    {       
       if (e.Row.RowType == DataControlRowType.DataRow)
        {
            จำนวน= Convert.ToInt64(DataBinder.Eval(e.Row.DataItem, "fileจำนวน"));
            ราคา= Convert.ToSingle(DataBinder.Eval(e.Row.DataItem, "fileราคา"));

               modTotal = (Convert.ToSingle(ราคา) * (Convert.ToInt64(จำนวน)));
              e.Row.Cells[6].Text = modTotal.ToString("#,###.0");


            }
        }
      }

   public decimal TotalUnitPrice;
   public decimal GetUnitPrice(decimal Price)
   {
       TotalUnitPrice += Price;
       return Price;
   }

   public decimal GetTotal()
   {
       return TotalUnitPrice;
   }

taKeyNames="id" OnRowCancelingEdit="modCancelCommand" 
                        OnRowCommand="grvDetail_RowCommand" OnRowDataBound="grvDetail_RowDataBound" 
                        OnRowDeleting="modDeleteCommand" OnRowEditing="modEditCommand" 
                        OnRowUpdating="modUpdateCommand" Width="100%" 
                        onselectedindexchanged="grvDetail_SelectedIndexChanged">
                             <RowStyle BackColor="#E7E7FF" ForeColor="#4A3C8C" HorizontalAlign="Center" />
                        <Columns>
                            <asp:TemplateField HeaderImageUrl="~/Imagefiles/Delete.gif" 
                                HeaderText="ลบข้อมูล">
                                <ItemTemplate>
                                    <asp:CheckBox ID="cbxDelete" runat="server" ToolTip="ติกเพื่อลบข้อมูล" />
                                </ItemTemplate>
                                <HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" />
                            </asp:TemplateField>
                            <%--  //////////////////////////////////////////// --%>
                                    <asp:TemplateField HeaderText=" กะ ">
                                        <HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" />
                            <ItemStyle HorizontalAlign="Center" VerticalAlign="Top" />
                                <ItemTemplate>
                                    <asp:Label ID="lblShift" runat="server"  Width ="50px"
                                        Text='<%# DataBinder.Eval(Container, "DataItem.shiftname") %>'></asp:Label>
                                </ItemTemplate>
                                <EditItemTemplate>
                                    <asp:DropDownList ID="ddlEditShift" runat="server" AutoPostBack="True" 
                                        CssClass="Bold_Pink">
                                    </asp:DropDownList>
                                </EditItemTemplate>
                            </asp:TemplateField>
                            
                            <%--  //////////////////////////////////////////// --%>
                                   <asp:TemplateField HeaderText="ลำดับที่"  >
                                       <HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" />
                            <ItemStyle HorizontalAlign="Center" VerticalAlign="Top" />
                                <ItemTemplate>
                                    <asp:Label ID="lblmatmixcount" runat="server"  Width ="50px"
                                        Text='<%# DataBinder.Eval(Container, "DataItem.matmixcount") %>'></asp:Label>
                                </ItemTemplate>
                                <EditItemTemplate>
                                    <asp:DropDownList ID="ddl_EditMatMixCount" runat="server" AutoPostBack="True" 
                                        CssClass="Bold_Pink">
                                        <asp:ListItem>1</asp:ListItem>
                                        <asp:ListItem>2</asp:ListItem>
                                        <asp:ListItem>3</asp:ListItem>
                                        <asp:ListItem>4</asp:ListItem>
                                        <asp:ListItem>5</asp:ListItem>
                                        <asp:ListItem>6</asp:ListItem>
                                        <asp:ListItem>7</asp:ListItem>
                                        <asp:ListItem>8</asp:ListItem>
                                        <asp:ListItem>9</asp:ListItem>
                                        <asp:ListItem>10</asp:ListItem>
                                    </asp:DropDownList>
                                </EditItemTemplate>
                            </asp:TemplateField>
                            
                            <%--  //////////////////////////////////////////// --%>
                            
                            <asp:TemplateField HeaderText="ID" SortExpression="id" Visible="false">
                                <ItemStyle HorizontalAlign="Left" VerticalAlign="Top" />
                                <HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" />
                                <ItemTemplate>
                                    <asp:Label ID="lblid" runat="server" Text='<%# Bind("id") %>'></asp:Label>
                                </ItemTemplate>
                            </asp:TemplateField>
                            
                            <%--  //////////////////////////////////////////// --%>
                            
                            <asp:TemplateField HeaderText="ชื่อวัตถุดิบผสม" SortExpression="matname">
                                <ItemStyle HorizontalAlign="Left" VerticalAlign="Top" />
                                <HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" />
                                <ItemTemplate>
                                    <asp:Label ID="lblmatname" runat="server" Text='<%# Bind("matname") %>'></asp:Label>
                                </ItemTemplate>
                            </asp:TemplateField>
                            
                            <%--  //////////////////////////////////////////// --%>
                            
                            <asp:TemplateField HeaderText="รหัสแผน" SortExpression="planid" 
                                Visible="false">
                                <ItemStyle HorizontalAlign="Left" VerticalAlign="Top" />
                                <HeaderStyle HorizontalAlign="Center" VerticalAlign="Top" />
                                <ItemTemplate>
                                    <asp:Label ID="lblplanid" runat="server" Text='<%# Bind("planid") %>'></asp:Label>
                                </ItemTemplate>
                            </asp:TemplateField>
                            
                            <%--  //////////////////////////////////////////// --%>
                            
                            <asp:TemplateField HeaderText="ชื่อเครื่องจักร" SortExpression="MacName" 
                                Visible="false">
                                <ItemStyle HorizontalAlign="Left" VerticalAlign="Top" />
                                <HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" />
                                <ItemTemplate>
                                    <asp:Label ID="lblMacName" runat="server" Text='<%# Bind("MacName") %>'></asp:Label>
                                </ItemTemplate>
                            </asp:TemplateField>
                            
                            <%--  //////////////////////////////////////////// --%>
                            
                            <asp:TemplateField HeaderText=" กะ " SortExpression="shiftid" 
                                Visible="false">
                                <ItemStyle HorizontalAlign="Center" VerticalAlign="Top" />
                                <HeaderStyle HorizontalAlign="Right" VerticalAlign="Middle" />
                                <ItemTemplate>
                                    <asp:Label ID="lblshiftname" runat="server" Text='<%# Bind("shiftid") %>'></asp:Label>
                                </ItemTemplate>
                            </asp:TemplateField>
                            
                            <%--  //////////////////////////////////////////// --%>
                            
                                <asp:TemplateField HeaderText="ประเภทวัตถุดิบ" FooterText="Total:" >
                                    <HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" />
                            <ItemStyle HorizontalAlign="Center" VerticalAlign="Top" Width="120px"/>
                                <ItemTemplate>
                                    <asp:Label ID="lblTypeMatDetName" runat="server"  Width="60px"
                                        Text='<%# DataBinder.Eval(Container, "DataItem.TypeMatDetName") %>'></asp:Label>
                                </ItemTemplate>
                                <EditItemTemplate>
                                    <asp:DropDownList ID="ddlEditTypeMatDetName" runat="server" AutoPostBack="True" 
                                        CssClass="Bold_Pink">
                                    </asp:DropDownList>
                                </EditItemTemplate>
                            </asp:TemplateField>
                            
                            <%--  //////////////////////////////////////////// --%>
                            
                            <asp:TemplateField HeaderText="รหัสเครื่องจักร" SortExpression="MacID" 
                                Visible="false">
                                <ItemStyle HorizontalAlign="Center" VerticalAlign="Top" />
                                <HeaderStyle HorizontalAlign="Right" VerticalAlign="Top" />
                                <ItemTemplate>
                                    <asp:Label ID="lblMacID" runat="server" 
                                        Text='<%# Bind("MacID") %>'></asp:Label>
                                </ItemTemplate>
                            </asp:TemplateField>
                            
                            <asp:TemplateField HeaderText="ชื่อวัตถุดิบผสม" SortExpression="MatID" 
                                Visible="false">
                                <ItemStyle HorizontalAlign="Center" VerticalAlign="Top" />
                                <HeaderStyle HorizontalAlign="Right" VerticalAlign="Middle" />
                                <ItemTemplate>
                                    <asp:Label ID="lblMatID" runat="server" Text='<%# Bind("MatID") %>'></asp:Label>
                                </ItemTemplate>
                            </asp:TemplateField>
                            <asp:TemplateField HeaderText="จำนวน kg" SortExpression="MatMixKg">
                                <ItemStyle HorizontalAlign="Center" VerticalAlign="Middle" />
                                <HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" />
                                <ItemTemplate>
                                    <asp:Label ID="lblMatMixKg" runat="server"  Width="100px"
                                    Text='<%#  GetUnitPrice(decimal.Parse(Eval("MatMixKg").ToString())).ToString("N2")%>'>     </asp:Label>
                                    
                             </ItemTemplate>
                    <FooterTemplate>
                        <%# lbltotal.Text = GetTotal().ToString("N2")%>                      ตรงบันทัดนี้เอา  lbltotal.Text =  ออกก็จะได้ผลรวมในgrid ครับ
                        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;
                    </FooterTemplate>
                     <FooterStyle Font-Bold="True"  HorizontalAlign="Right" />
                    <ItemStyle HorizontalAlign="Center" Width="120px"  /> 
                            </asp:TemplateField>
                        </Columns>
                         <FooterStyle BackColor="#B5C7DE" ForeColor="#4A3C8C" HorizontalAlign="Right" 
                                 Font-Bold="true" Height="30px"  />
                        <AlternatingRowStyle BackColor="White" />
                        <HeaderStyle  CssClass ="H_Orange" />
                    </asp:GridView>