ASP.Net Looping Through Gridview After adding Group Row - asp.net

Question

In a GridView I am adding Grouping rows to the underlying table in the RowDataBound, but when I ApplyChanges and loop through each GridViewRow not all rows can be tested for TextBox value etc, the number of rows is reduced by the number of grouping rows inserted. Although it does loop through the grouping rows which I ignore, and misses the last n rows.
Private tmpSiteName As String = ""
Private Sub gvVehicles_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles gvVehicles.RowDataBound
If e.Row.RowType = DataControlRowType.DataRow Then
Dim drv As DataRowView = DirectCast(e.Row.DataItem, DataRowView)
If tmpSiteName <> drv("lcname").ToString() Then
tmpSiteName = drv("lcname").ToString()
Dim tbl As Table = TryCast(e.Row.Parent, Table)
If tbl IsNot Nothing Then
Dim row As New GridViewRow(-1, -1, DataControlRowType.DataRow, DataControlRowState.Normal)
Dim cell As New TableCell()
' Span the row across all of the columns in the Gridview
cell.ColumnSpan = Me.gvVehicles.Columns.Count
cell.Width = Unit.Percentage(100)
'cell.Style.Add("font-weight", "bold")
cell.Style.Add("background-color", "#f5f5f5")
cell.Style.Add("color", "#000000")
Dim span As New HtmlGenericControl("span")
span.InnerHtml = tmpSiteName
cell.Controls.Add(span)
row.Cells.Add(cell)
tbl.Rows.AddAt(tbl.Rows.Count - 1, row)
End If
End If
End If
End Sub
Private Sub ApplyChanges()
Dim AuctionDB As fleet.AuctionDB = New fleet.AuctionDB
Dim OldFleetNo As String = ""
Dim NewFleetNo As String = ""
Dim OldReserve As Integer = 0
Dim NewReserve As Integer = 0
Dim MTA As Long = 0
Dim Sitekey As String = ""
Dim vcaudit As Long = 0
Dim i As Integer = gvVehicles.Rows.Count
Try
For Each DRow As GridViewRow In gvVehicles.Rows
Sitekey = TryCast(DRow.FindControl("hiddenSitekey"), HiddenField).Value
MTA = Val(TryCast(DRow.FindControl("hiddenMTA"), HiddenField).Value)
strChange = ""
' The Grouping rows throw up funny results, but we can catch MTA = 0
If MTA > 0 Then
OldFleetNo = TryCast(DRow.FindControl("hiddenFleetNo"), HiddenField).Value
NewFleetNo = TryCast(DRow.FindControl("txtFleetNo"), TextBox).Text
If NewFleetNo <> OldFleetNo Then
vcaudit = AuctionDB.FleetUpdates(Sitekey, MTA, "FLEET NO", OldReserve, NewFleetNo, Session("user_name"))
updateCount += 1
strChange = "Fleet No. changed from " & OldFleetNo & " to " & NewFleetNo & "<br /><br />"
End If
End If
Next DRow
Catch ex As Exception
ShowMessage("Error: " & ex.Message, "alert-danger")
End Try
End Sub