Custom Aggregate Function Problem

[Anon]

I'm having a problem calculating my custom aggregate sum function for nested groups.

For example, I have a product group, a product, and then several rows pertaining to that product (so there are two groupings: the main product group > then the individual product and its data). Then, for each grouping I have a footer which calculates the sum of the column based on the value of another column in that row.

What I'd like to see is something like this assuming a product group with 2 products. It would calculate the footer total for each product in that column if the first column's value is say 'Row 3' or 'Row 4' and then for the top product grouping (for 'Product Group 1') would calculate the values from the other footers.

Product Group 1
    Product 1
        Row 1 | 1 | 1 | 1 | 1 |
        Row 2 | 1 | 1 | 1 | 1 |
        Row 3 | 2 | 2 | 2 | 1 |
        Row 4 | 2 | 2 | 1 | 1 |
   [Footer]   | 4 | 4 | 3 | 2 |
    Product 2
        Row 1 | 1 | 1 | 1 | 1 |
        Row 2 | 1 | 1 | 1 | 1 |
        Row 3 | 2 | 2 | 2 | 1 |
        Row 4 | 2 | 2 | 1 | 1 |
   [Footer]   | 4 | 4 | 3 | 2 |
[Footer]      | 8 | 8 | 6 | 4 |

I have it set up so each product's footer calculates the individual product's footer correctly, but not the top most group footer (the product grouping), it only calculates the last individual product's total as in the screenshot I attached. I'm not quite sure how to grab the totals from previous footers of the same grouping.

Here is my custom aggregate function as is now:

Protected Sub RadGrid1_CustomAggregate(ByVal sender As Object, ByVal e As GridCustomAggregateEventArgs) Handles RadGrid1.CustomAggregate

        If e.Column.UniqueName = "Row" Then
            e.Result = ""
        Else
            Dim length As Integer = RadGrid1.MasterTableView.GetItems(GridItemType.GroupHeader).Length
            For i As Integer = 0 To length - 1

                Dim total As Double = 0

                Dim groupHeader As GridGroupHeaderItem = DirectCast(RadGrid1.MasterTableView.GetItems(GridItemType.GroupHeader)(i), GridGroupHeaderItem)
                Dim children As GridItem() = groupHeader.GetChildItems()

                For Each child As GridItem In children
                    If TypeOf child Is GridDataItem Then
                        Dim childItem As GridDataItem = TryCast(child, GridDataItem)

                        Dim rowText As String = childItem.Item("Row").Text

                        If rowText = "Row3" OrElse rowText = "Row4" Then
                            total += childItem.Item("Value").Text
                        End If
                    End If
                Next
                e.Result = total
            Next
        End If
    End Sub

Sorry if this is a dumb question, but I'm a little stuck here.

[Martin]

Hello Anon,

You can use the GroupIndex property of the GridGroupFooterItem and GridGroupHeaderItem objects to distinguish which footer item belongs to the relevant group and calculate its aggregate accordingly. I have attached a small sample that demonstrates this approach.

I hope this helps.

Regards,
Martin
the Telerik team