Group Total and Grand Total in GridView - Part 2

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This post is a continuation of a series. Please look at the end of this post for more information

Previously I blogged Group Total and Grand Total in Grid View, which has some good example for showing Group Total and Grand Total on records showing on the Grid.

On the same concept, I am planning to extend some more functionality with Group Total and Grand Total on records in Grid View.

Note:

1. As defined in previous post, to implement these examples; all the records must show in a single page of the Grid View (So, no pagination). Because for calculating the Group Total and Grand Total, the code required all the records must be in loop.
2. The records must be sorted on the group wise. So all the records related to a particular group will show one after another. So it will be useful for calculating cumulative values together. Keeping records in different group will be considered as it another separate group and cumulative values will be calculated as another separate group.
3. There was a question in asp.net forums about Totals in GridView (http://forums.asp.net/t/1755649.aspx/1/10?Totals+row+in+GridView). I pointed the previous post as reply and I got couple of nice enhancement on the same example. I am taking the same requirements first here to show with a perfect example and then giving with some additional enhancements.

In the both the examples listed below, I have an XML file defined in the project for binding the records to the Grid View. The XML file is as defined below:


First Requirement:

1. The records defined in the XML should bound to the Grid View in a normal way.
2. The records should be grouped by Customer Name and the Group Total should be under each of the Group.
3. The Grand Total of all the records should be shown after all the records in the Grid.
4. When each group started, the Customer Name should be shown as the header of each group.
5. The Group Header, Group Total and Grand Total rows background color must be in predefined style.

In this requirement, the first three points already been implemented in the previous post. We are going to implement fourth requirement additionally.

The XML

<?xml version="1.0" encoding="utf-8" ?>
<Orders>
  <Order OrderID="10643" CustomerID="ALFKI" CompanyName="Alfreds Futterkiste" ContactTitle="Sales Representative" Address="Obere Str. 5711" City="Berlin" Country="Germany" Phone="030-0074321" Fax="030-0076545" ProductID="28" ProductName="Rössle Sauerkraut" UnitPrice="45.60" Quantity="15" Discount="0.25" Amount="683.75"/>
  <Order OrderID="10643" CustomerID="ALFKI" CompanyName="Alfreds Futterkiste" ContactTitle="Sales Representative" Address="Obere Str. 5711" City="Berlin" Country="Germany" Phone="030-0074321" Fax="030-0076545" ProductID="39" ProductName="Chartreuse verte" UnitPrice="18.00" Quantity="21" Discount="0.25" Amount="377.75"/>
  <Order OrderID="10643" CustomerID="ALFKI" CompanyName="Alfreds Futterkiste" ContactTitle="Sales Representative" Address="Obere Str. 5711" City="Berlin" Country="Germany" Phone="030-0074321" Fax="030-0076545" ProductID="46" ProductName="Spegesild" UnitPrice="12.00" Quantity="2" Discount="0.25" Amount="23.75"/>
  <Order OrderID="10692" CustomerID="ALFKI" CompanyName="Alfreds Futterkiste" ContactTitle="Sales Representative" Address="Obere Str. 5711" City="Berlin" Country="Germany" Phone="030-0074321" Fax="030-0076545" ProductID="63" ProductName="Vegie-spread" UnitPrice="43.90" Quantity="20" Discount="0.00" Amount="878.00"/>
  <Order OrderID="10702" CustomerID="ALFKI" CompanyName="Alfreds Futterkiste" ContactTitle="Sales Representative" Address="Obere Str. 5711" City="Berlin" Country="Germany" Phone="030-0074321" Fax="030-0076545" ProductID="3" ProductName="Aniseed Syrup" UnitPrice="10.00" Quantity="6" Discount="0.00" Amount="60.00"/>
  <Order OrderID="10308" CustomerID="ANATR" CompanyName="Ana Trujillo Emparedados y helados" ContactTitle="Owner" Address="Avda. de la Constitución 2222" City="México D.F." Country="Mexico" Phone="(5) 555-4729" Fax="(5) 555-3745" ProductID="69" ProductName="Gudbrandsdalsost" UnitPrice="28.80" Quantity="1" Discount="0.00" Amount="28.80"/>
  <Order OrderID="10308" CustomerID="ANATR" CompanyName="Ana Trujillo Emparedados y helados" ContactTitle="Owner" Address="Avda. de la Constitución 2222" City="México D.F." Country="Mexico" Phone="(5) 555-4729" Fax="(5) 555-3745" ProductID="70" ProductName="Outback Lager" UnitPrice="12.00" Quantity="5" Discount="0.00" Amount="60.00"/>
  <Order OrderID="10926" CustomerID="ANATR" CompanyName="Ana Trujillo Emparedados y helados" ContactTitle="Owner" Address="Avda. de la Constitución 2222" City="México D.F." Country="Mexico" Phone="(5) 555-4729" Fax="(5) 555-3745" ProductID="72" ProductName="Mozzarella di Giovanni" UnitPrice="34.80" Quantity="10" Discount="0.00" Amount="348.00"/>
  <Order OrderID="10355" CustomerID="AROUT" CompanyName="Around the Horn" ContactTitle="Sales Representative" Address="120 Hanover Sq." City="London" Country="UK" Phone="(171) 555-7788" Fax="(171) 555-6750" ProductID="24" ProductName="Guaraná Fantástica" UnitPrice="3.60" Quantity="25" Discount="0.00" Amount="90.00"/>
  <Order OrderID="10953" CustomerID="AROUT" CompanyName="Around the Horn" ContactTitle="Sales Representative" Address="120 Hanover Sq." City="London" Country="UK" Phone="(171) 555-7788" Fax="(171) 555-6750" ProductID="31" ProductName="Gorgonzola Telino" UnitPrice="12.50" Quantity="50" Discount="0.05" Amount="624.95"/>
  <Order OrderID="11016" CustomerID="AROUT" CompanyName="Around the Horn" ContactTitle="Sales Representative" Address="120 Hanover Sq." City="London" Country="UK" Phone="(171) 555-7788" Fax="(171) 555-6750" ProductID="31" ProductName="Gorgonzola Telino" UnitPrice="12.50" Quantity="15" Discount="0.00" Amount="187.50"/>
  <Order OrderID="11016" CustomerID="AROUT" CompanyName="Around the Horn" ContactTitle="Sales Representative" Address="120 Hanover Sq." City="London" Country="UK" Phone="(171) 555-7788" Fax="(171) 555-6750" ProductID="36" ProductName="Inlagd Sill" UnitPrice="19.00" Quantity="16" Discount="0.00" Amount="304.00"/>
  <Order OrderID="10278" CustomerID="BERGS" CompanyName="Berglunds snabbköp" ContactTitle="Order Administrator" Address="Berguvsvägen  8" City="Luleå" Country="Sweden" Phone="0921-12 34 65" Fax="0921-12 34 67" ProductID="44" ProductName="Gula Malacca" UnitPrice="15.50" Quantity="16" Discount="0.00" Amount="248.00"/>
  <Order OrderID="10278" CustomerID="BERGS" CompanyName="Berglunds snabbköp" ContactTitle="Order Administrator" Address="Berguvsvägen  8" City="Luleå" Country="Sweden" Phone="0921-12 34 65" Fax="0921-12 34 67" ProductID="59" ProductName="Raclette Courdavault" UnitPrice="44.00" Quantity="15" Discount="0.00" Amount="660.00"/>
  <Order OrderID="10278" CustomerID="BERGS" CompanyName="Berglunds snabbköp" ContactTitle="Order Administrator" Address="Berguvsvägen  8" City="Luleå" Country="Sweden" Phone="0921-12 34 65" Fax="0921-12 34 67" ProductID="63" ProductName="Vegie-spread" UnitPrice="35.10" Quantity="8" Discount="0.00" Amount="280.80"/>
  <Order OrderID="10278" CustomerID="BERGS" CompanyName="Berglunds snabbköp" ContactTitle="Order Administrator" Address="Berguvsvägen  8" City="Luleå" Country="Sweden" Phone="0921-12 34 65" Fax="0921-12 34 67" ProductID="73" ProductName="Röd Kaviar" UnitPrice="12.00" Quantity="25" Discount="0.00" Amount="300.00"/>
  <Order OrderID="10280" CustomerID="BERGS" CompanyName="Berglunds snabbköp" ContactTitle="Order Administrator" Address="Berguvsvägen  8" City="Luleå" Country="Sweden" Phone="0921-12 34 65" Fax="0921-12 34 67" ProductID="24" ProductName="Guaraná Fantástica" UnitPrice="3.60" Quantity="12" Discount="0.00" Amount="43.20"/>
</Orders>

The ASPX script

<asp:GridView ID="grdViewOrders" runat="server" AutoGenerateColumns="False" TabIndex="1"
    Width="100%" DataSourceID="XmlDataSource1"
    CellPadding="4" ForeColor="Black" GridLines="Vertical"
    OnRowDataBound="grdViewOrders_RowDataBound"
    onrowcreated="grdViewOrders_RowCreated" BackColor="White" 
    BorderColor="#DEDFDE" BorderStyle="None" BorderWidth="1px">            
    <Columns>
        <asp:BoundField DataField="OrderID" HeaderText="OrderID">
            <ItemStyle HorizontalAlign="Left"></ItemStyle>
        </asp:BoundField>
        <asp:BoundField DataField="ProductName" HeaderText="ProductName">
            <ItemStyle HorizontalAlign="Left"></ItemStyle>
        </asp:BoundField>
        <asp:BoundField DataField="UnitPrice" HeaderText="UnitPrice">
            <ItemStyle HorizontalAlign="Right"></ItemStyle>
        </asp:BoundField>
        <asp:BoundField DataField="Quantity" HeaderText="Quantity">
            <ItemStyle HorizontalAlign="Right"></ItemStyle>
        </asp:BoundField>
        <asp:BoundField DataField="Discount" HeaderText="Discount">
            <ItemStyle HorizontalAlign="Right"></ItemStyle>
        </asp:BoundField>
        <asp:BoundField DataField="Amount" HeaderText="Amount">
            <ItemStyle HorizontalAlign="Right"></ItemStyle>
        </asp:BoundField>
    </Columns>
    <RowStyle BackColor="#F7F7DE" BorderStyle="Solid" BorderWidth="1px" BorderColor="Black" />
    <FooterStyle BackColor="#CCCC99" />
    <PagerStyle BackColor="#F7F7DE" ForeColor="Black" HorizontalAlign="Right" />
    <SelectedRowStyle BackColor="#CE5D5A" ForeColor="White" Font-Bold="True" />
    <HeaderStyle BackColor="#6B696B" Font-Bold="True" ForeColor="White" BorderStyle="Solid" BorderWidth="1px" BorderColor="Black" />
    <AlternatingRowStyle BackColor="White" BorderStyle="Solid" BorderWidth="1px" BorderColor="Black" />
    <SortedAscendingCellStyle BackColor="#FBFBF2" />
    <SortedAscendingHeaderStyle BackColor="#848384" />
    <SortedDescendingCellStyle BackColor="#EAEAD3" />
    <SortedDescendingHeaderStyle BackColor="#575357" />
</asp:GridView>

The C# Code behind

public partial class Example1 : System.Web.UI.Page
{
    // To keep track of the previous row Group Identifier
    string strPreviousRowID = string.Empty;
    // To keep track the Index of Group Total
    int intSubTotalIndex = 1;

    // To temporarily store Sub Total
    double dblSubTotalUnitPrice = 0;
    double dblSubTotalQuantity = 0;
    double dblSubTotalDiscount = 0;
    double dblSubTotalAmount = 0;

    // To temporarily store Grand Total
    double dblGrandTotalUnitPrice = 0;
    double dblGrandTotalQuantity = 0;
    double dblGrandTotalDiscount = 0;
    double dblGrandTotalAmount = 0;

    protected void Page_Load(object sender, EventArgs e) {    }
 
    /// <summary>
    /// Event fires for every row creation
    /// Used for creating SubTotal row when next group starts by adding Group Total at previous row manually
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected void grdViewOrders_RowCreated(object sender, GridViewRowEventArgs e)
    {
        bool IsSubTotalRowNeedToAdd = false;
        bool IsGrandTotalRowNeedtoAdd = false;

        if ((strPreviousRowID != string.Empty) && (DataBinder.Eval(e.Row.DataItem, "CustomerID") != null))
            if (strPreviousRowID != DataBinder.Eval(e.Row.DataItem, "CustomerID").ToString())
                IsSubTotalRowNeedToAdd = true;

        if ((strPreviousRowID != string.Empty) && (DataBinder.Eval(e.Row.DataItem, "CustomerID") == null))
        {
            IsSubTotalRowNeedToAdd = true;
            IsGrandTotalRowNeedtoAdd = true;
            intSubTotalIndex = 0;
        }

        #region Inserting first Row and populating fist Group Header details
        if ((strPreviousRowID == string.Empty) && (DataBinder.Eval(e.Row.DataItem, "CustomerID") != null))
        {
            GridView grdViewOrders = (GridView)sender;

            GridViewRow row = new GridViewRow(0, 0, DataControlRowType.DataRow, DataControlRowState.Insert);

            TableCell cell = new TableCell();
            cell.Text = "Customer Name : " + DataBinder.Eval(e.Row.DataItem, "CompanyName").ToString();
            cell.ColumnSpan = 6;
            cell.CssClass = "GroupHeaderStyle";
            row.Cells.Add(cell);

            grdViewOrders.Controls[0].Controls.AddAt(e.Row.RowIndex + intSubTotalIndex, row);
            intSubTotalIndex++;
        }
        #endregion

        if (IsSubTotalRowNeedToAdd)
        {
            #region Adding Sub Total Row
            GridView grdViewOrders = (GridView)sender;

            // Creating a Row
            GridViewRow row = new GridViewRow(0, 0, DataControlRowType.DataRow, DataControlRowState.Insert);

            //Adding Total Cell 
            TableCell cell = new TableCell();
            cell.Text = "Sub Total";
            cell.HorizontalAlign = HorizontalAlign.Left;
            cell.ColumnSpan = 2;
            cell.CssClass = "SubTotalRowStyle";
            row.Cells.Add(cell);

            //Adding Unit Price Column
            cell = new TableCell();
            cell.Text = string.Format("{0:0.00}", dblSubTotalUnitPrice);
            cell.HorizontalAlign = HorizontalAlign.Right;
            cell.CssClass = "SubTotalRowStyle";
            row.Cells.Add(cell);

            //Adding Quantity Column
            cell = new TableCell();
            cell.Text = string.Format("{0:0.00}", dblSubTotalQuantity);
            cell.HorizontalAlign = HorizontalAlign.Right;
            cell.CssClass = "SubTotalRowStyle";
            row.Cells.Add(cell);

            //Adding Discount Column
            cell = new TableCell();
            cell.Text = string.Format("{0:0.00}", dblSubTotalDiscount);
            cell.HorizontalAlign = HorizontalAlign.Right;
            cell.CssClass = "SubTotalRowStyle";
            row.Cells.Add(cell);

            //Adding Amount Column
            cell = new TableCell();
            cell.Text = string.Format("{0:0.00}", dblSubTotalAmount);
            cell.HorizontalAlign = HorizontalAlign.Right;
            cell.CssClass = "SubTotalRowStyle";
            row.Cells.Add(cell);

            //Adding the Row at the RowIndex position in the Grid
            grdViewOrders.Controls[0].Controls.AddAt(e.Row.RowIndex + intSubTotalIndex, row);
            intSubTotalIndex++;
            #endregion

            #region Adding Next Group Header Details
            if (DataBinder.Eval(e.Row.DataItem, "CustomerID") != null)
            {
                row = new GridViewRow(0, 0, DataControlRowType.DataRow, DataControlRowState.Insert);

                cell = new TableCell();
                cell.Text = "Customer Name : " + DataBinder.Eval(e.Row.DataItem, "CompanyName").ToString();
                cell.ColumnSpan = 6;
                cell.CssClass = "GroupHeaderStyle";
                row.Cells.Add(cell);

                grdViewOrders.Controls[0].Controls.AddAt(e.Row.RowIndex + intSubTotalIndex, row);
                intSubTotalIndex++;
            }
            #endregion

            #region Reseting the Sub Total Variables
            dblSubTotalUnitPrice = 0;
            dblSubTotalQuantity = 0;
            dblSubTotalDiscount = 0;
            dblSubTotalAmount = 0;
            #endregion
        }
        if (IsGrandTotalRowNeedtoAdd)
        {
            #region Grand Total Row
            GridView grdViewOrders = (GridView)sender;

            // Creating a Row
            GridViewRow row = new GridViewRow(0, 0, DataControlRowType.DataRow, DataControlRowState.Insert);

            //Adding Total Cell 
            TableCell cell = new TableCell();
            cell.Text = "Grand Total";
            cell.HorizontalAlign = HorizontalAlign.Left;
            cell.ColumnSpan = 2;
            cell.CssClass = "GrandTotalRowStyle";
            row.Cells.Add(cell);

            //Adding Unit Price Column
            cell = new TableCell();
            cell.Text = string.Format("{0:0.00}", dblGrandTotalUnitPrice);
            cell.HorizontalAlign = HorizontalAlign.Right;
            cell.CssClass = "GrandTotalRowStyle";
            row.Cells.Add(cell);

            //Adding Quantity Column
            cell = new TableCell();
            cell.Text = string.Format("{0:0.00}", dblGrandTotalQuantity);
            cell.HorizontalAlign = HorizontalAlign.Right;
            cell.CssClass = "GrandTotalRowStyle";
            row.Cells.Add(cell);

            //Adding Discount Column
            cell = new TableCell();
            cell.Text = string.Format("{0:0.00}", dblGrandTotalDiscount);
            cell.HorizontalAlign = HorizontalAlign.Right;
            cell.CssClass = "GrandTotalRowStyle";
            row.Cells.Add(cell);

            //Adding Amount Column
            cell = new TableCell();
            cell.Text = string.Format("{0:0.00}", dblGrandTotalAmount);
            cell.HorizontalAlign = HorizontalAlign.Right;
            cell.CssClass = "GrandTotalRowStyle";
            row.Cells.Add(cell);

            //Adding the Row at the RowIndex position in the Grid
            grdViewOrders.Controls[0].Controls.AddAt(e.Row.RowIndex, row);
            #endregion
        }
    }
    /// <summary>
    /// Event fires when data binds to each row
    /// Used for calculating Group Total 
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    protected void grdViewOrders_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        // This is for cumulating the values
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            strPreviousRowID = DataBinder.Eval(e.Row.DataItem, "CustomerID").ToString();

            double dblUnitPrice = Convert.ToDouble(DataBinder.Eval(e.Row.DataItem, "UnitPrice").ToString());
            double dblQuantity = Convert.ToDouble(DataBinder.Eval(e.Row.DataItem, "Quantity").ToString());
            double dblDiscount = Convert.ToDouble(DataBinder.Eval(e.Row.DataItem, "Discount").ToString());
            double dblAmount = Convert.ToDouble(DataBinder.Eval(e.Row.DataItem, "Amount").ToString());

            // Cumulating Sub Total
            dblSubTotalUnitPrice += dblUnitPrice;
            dblSubTotalQuantity += dblQuantity;
            dblSubTotalDiscount += dblDiscount;
            dblSubTotalAmount += dblAmount;

            // Cumulating Grand Total
            dblGrandTotalUnitPrice += dblUnitPrice;
            dblGrandTotalQuantity += dblQuantity;
            dblGrandTotalDiscount += dblDiscount;
            dblGrandTotalAmount += dblAmount;
        }
    }
}

The VB Code behind

Public Class Example1
    Inherits System.Web.UI.Page

    ' To keep track of the previous row Group Identifier
    Dim strPreviousRowID As String = String.Empty
    ' To keep track the Index of Group Total
    Dim intSubTotalIndex As Integer = 1

    ' To temporarily store Sub Total
    Dim dblSubTotalUnitPrice As Double = 0
    Dim dblSubTotalQuantity As Double = 0
    Dim dblSubTotalDiscount As Double = 0
    Dim dblSubTotalAmount As Double = 0

    ' To temporarily store Grand Total
    Dim dblGrandTotalUnitPrice As Double = 0
    Dim dblGrandTotalQuantity As Double = 0
    Dim dblGrandTotalDiscount As Double = 0
    Dim dblGrandTotalAmount As Double = 0

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
    End Sub

    ''' <summary>
    ''' Event fires when data binds to each row
    ''' Used for calculating Group Total 
    ''' </summary>
    ''' <param name="sender"></param>
    ''' <param name="e"></param>
    ''' <remarks></remarks>
    Protected Sub grdViewOrders_RowDataBound(sender As Object, e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles grdViewOrders.RowDataBound
        ' This is for cumulating the values
        If e.Row.RowType = DataControlRowType.DataRow Then
            strPreviousRowID = DataBinder.Eval(e.Row.DataItem, "CustomerID").ToString()

            Dim dblUnitPrice As Double = Convert.ToDouble(DataBinder.Eval(e.Row.DataItem, "UnitPrice").ToString())
            Dim dblQuantity As Double = Convert.ToDouble(DataBinder.Eval(e.Row.DataItem, "Quantity").ToString())
            Dim dblDiscount As Double = Convert.ToDouble(DataBinder.Eval(e.Row.DataItem, "Discount").ToString())
            Dim dblAmount As Double = Convert.ToDouble(DataBinder.Eval(e.Row.DataItem, "Amount").ToString())

            ' Cumulating Sub Total
            dblSubTotalUnitPrice += dblUnitPrice
            dblSubTotalQuantity += dblQuantity
            dblSubTotalDiscount += dblDiscount
            dblSubTotalAmount += dblAmount

            ' Cumulating Grand Total
            dblGrandTotalUnitPrice += dblUnitPrice
            dblGrandTotalQuantity += dblQuantity
            dblGrandTotalDiscount += dblDiscount
            dblGrandTotalAmount += dblAmount
        End If
    End Sub

    ''' <summary>
    ''' Event fires for every row creation
    ''' Used for creating SubTotal row when next group starts by adding Group Total at previous row manually
    ''' </summary>
    ''' <param name="sender"></param>
    ''' <param name="e"></param>
    ''' <remarks></remarks>
    Protected Sub grdViewOrders_RowCreated(sender As Object, e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles grdViewOrders.RowCreated
        Dim IsSubTotalRowNeedToAdd As Boolean = False
        Dim IsGrandTotalRowNeedtoAdd As Boolean = False

        If (strPreviousRowID <> String.Empty) AndAlso (DataBinder.Eval(e.Row.DataItem, "CustomerID") IsNot Nothing) Then
            If strPreviousRowID <> DataBinder.Eval(e.Row.DataItem, "CustomerID").ToString() Then
                IsSubTotalRowNeedToAdd = True
            End If
        End If

        If (strPreviousRowID <> String.Empty) AndAlso (DataBinder.Eval(e.Row.DataItem, "CustomerID") Is Nothing) Then
            IsSubTotalRowNeedToAdd = True
            IsGrandTotalRowNeedtoAdd = True
            intSubTotalIndex = 0
        End If

        ' "Inserting first Row and populating fist Group Header details"
        If (strPreviousRowID = String.Empty) AndAlso (DataBinder.Eval(e.Row.DataItem, "CustomerID") IsNot Nothing) Then
            Dim grdViewOrders As GridView = DirectCast(sender, GridView)

            Dim row As New GridViewRow(0, 0, DataControlRowType.DataRow, DataControlRowState.Insert)

            Dim cell As New TableCell()
            cell.Text = "Customer Name : " & DataBinder.Eval(e.Row.DataItem, "CompanyName").ToString()
            cell.ColumnSpan = 6
            cell.CssClass = "GroupHeaderStyle"
            row.Cells.Add(cell)

            grdViewOrders.Controls(0).Controls.AddAt(e.Row.RowIndex + intSubTotalIndex, row)
            intSubTotalIndex += 1
        End If


        If IsSubTotalRowNeedToAdd Then
            ' "Adding Sub Total Row"
            Dim grdViewOrders As GridView = DirectCast(sender, GridView)

            ' Creating a Row
            Dim row As New GridViewRow(0, 0, DataControlRowType.DataRow, DataControlRowState.Insert)

            'Adding Total Cell 
            Dim cell As New TableCell()
            cell.Text = "Sub Total"
            cell.HorizontalAlign = HorizontalAlign.Left
            cell.ColumnSpan = 2
            cell.CssClass = "SubTotalRowStyle"
            row.Cells.Add(cell)

            'Adding Unit Price Column
            cell = New TableCell()
            cell.Text = String.Format("{0:0.00}", dblSubTotalUnitPrice)
            cell.HorizontalAlign = HorizontalAlign.Right
            cell.CssClass = "SubTotalRowStyle"
            row.Cells.Add(cell)

            'Adding Quantity Column
            cell = New TableCell()
            cell.Text = String.Format("{0:0.00}", dblSubTotalQuantity)
            cell.HorizontalAlign = HorizontalAlign.Right
            cell.CssClass = "SubTotalRowStyle"
            row.Cells.Add(cell)

            'Adding Discount Column
            cell = New TableCell()
            cell.Text = String.Format("{0:0.00}", dblSubTotalDiscount)
            cell.HorizontalAlign = HorizontalAlign.Right
            cell.CssClass = "SubTotalRowStyle"
            row.Cells.Add(cell)

            'Adding Amount Column
            cell = New TableCell()
            cell.Text = String.Format("{0:0.00}", dblSubTotalAmount)
            cell.HorizontalAlign = HorizontalAlign.Right
            cell.CssClass = "SubTotalRowStyle"
            row.Cells.Add(cell)

            'Adding the Row at the RowIndex position in the Grid
            grdViewOrders.Controls(0).Controls.AddAt(e.Row.RowIndex + intSubTotalIndex, row)
            intSubTotalIndex += 1

            ' "Adding Next Group Header Details"
            If DataBinder.Eval(e.Row.DataItem, "CustomerID") IsNot Nothing Then
                row = New GridViewRow(0, 0, DataControlRowType.DataRow, DataControlRowState.Insert)

                cell = New TableCell()
                cell.Text = "Customer Name : " & DataBinder.Eval(e.Row.DataItem, "CompanyName").ToString()
                cell.ColumnSpan = 6
                cell.CssClass = "GroupHeaderStyle"
                row.Cells.Add(cell)

                grdViewOrders.Controls(0).Controls.AddAt(e.Row.RowIndex + intSubTotalIndex, row)
                intSubTotalIndex += 1
            End If

            ' "Reseting the Sub Total Variables"
            dblSubTotalUnitPrice = 0
            dblSubTotalQuantity = 0
            dblSubTotalDiscount = 0

            dblSubTotalAmount = 0
        End If
        If IsGrandTotalRowNeedtoAdd Then
            ' "Grand Total Row"
            Dim grdViewOrders As GridView = DirectCast(sender, GridView)

            ' Creating a Row
            Dim row As New GridViewRow(0, 0, DataControlRowType.DataRow, DataControlRowState.Insert)

            'Adding Total Cell 
            Dim cell As New TableCell()
            cell.Text = "Grand Total"
            cell.HorizontalAlign = HorizontalAlign.Left
            cell.ColumnSpan = 2
            cell.CssClass = "GrandTotalRowStyle"
            row.Cells.Add(cell)

            'Adding Unit Price Column
            cell = New TableCell()
            cell.Text = String.Format("{0:0.00}", dblGrandTotalUnitPrice)
            cell.HorizontalAlign = HorizontalAlign.Right
            cell.CssClass = "GrandTotalRowStyle"
            row.Cells.Add(cell)

            'Adding Quantity Column
            cell = New TableCell()
            cell.Text = String.Format("{0:0.00}", dblGrandTotalQuantity)
            cell.HorizontalAlign = HorizontalAlign.Right
            cell.CssClass = "GrandTotalRowStyle"
            row.Cells.Add(cell)

            'Adding Discount Column
            cell = New TableCell()
            cell.Text = String.Format("{0:0.00}", dblGrandTotalDiscount)
            cell.HorizontalAlign = HorizontalAlign.Right
            cell.CssClass = "GrandTotalRowStyle"
            row.Cells.Add(cell)

            'Adding Amount Column
            cell = New TableCell()
            cell.Text = String.Format("{0:0.00}", dblGrandTotalAmount)
            cell.HorizontalAlign = HorizontalAlign.Right
            cell.CssClass = "GrandTotalRowStyle"
            row.Cells.Add(cell)

            'Adding the Row at the RowIndex position in the Grid

            grdViewOrders.Controls(0).Controls.AddAt(e.Row.RowIndex, row)
        End If

    End Sub
End Class

The Style Sheet

.SubTotalRowStyle{
    border:solid 1px Black;
    background-color:#F5A9BC;
    font-weight:bold;
}
.GrandTotalRowStyle{
    border:solid 1px Black;  
    background-color:Gray;
    font-weight:bold;
}
    .GroupHeaderStyle{
    border:solid 1px Black;
    background-color:#81BEF7;
    font-weight:bold;
}
.Spliter
{
    border-left:none;
    border-right:none;
    background-color:Aqua;
}

The Screen shot of the code output is:

Second Requirement

Addition to the above requirement mentioned in the first requirement, I need to give a empty space between each group sections. So each group sections will be separated clearly.

The implementation is as similar as above code, but we need to add required code for giving empty row after each group section completed. It means, after Group Total Completed.

So all the code is same, but additionally below section of code required to be added in the RowCreated event between Adding Sub Total Row region and Adding Next Group Header Details region (Adding Empty Row after each Group Total region in the code).
The C# Code

row = new GridViewRow(0, 0, DataControlRowType.DataRow, DataControlRowState.Insert);

cell = new TableCell();
cell.Text = string.Empty;
cell.Height = Unit.Parse("10px");
cell.ColumnSpan = 6;
row.Cells.Add(cell);

grdViewOrders.Controls[0].Controls.AddAt(e.Row.RowIndex + intSubTotalIndex, row);
intSubTotalIndex++;

The VB Code

row = New GridViewRow(0, 0, DataControlRowType.DataRow, DataControlRowState.Insert)

cell = New TableCell()
cell.Text = String.Empty
cell.Height = Unit.Parse("10px")
cell.ColumnSpan = 6
row.Cells.Add(cell)

grdViewOrders.Controls(0).Controls.AddAt(e.Row.RowIndex + intSubTotalIndex, row)
intSubTotalIndex += 1

The Screen shot of the code output is:

Download the working source code in C# here and in VB here.

The other links on Group Total, Grand Total in Grid View:

1. Group Total, Grand Total in Grid View - Part 1
2. Group Total, Grand Total in Grid View - Part 2
3. Group Total, Grand Total in Grid View - Part 3
4. Group Total, Grand Total in Grid View - Part 4
5. Group Total, Grand Total in Grid View - Part 5