Thank you for answering.

What I am doing is something like a filesystem tree, containing :

- Folders that can contain Folders and Files

- Files

So I've got 2 FieldLayouts and they are assigned to an Item by checking the item type on grid_AssigningFieldLayoutToItem method.

It displays fine.

If I try to sort the grid, I need to totally expand rows like this (for 2 levels :

Dim level = 2
While level > 0
  For Each rec In grid.GetRecordsInView(True)
    rec.IsExpanded = True
  Next
  level -= 1
End While

If I try using such a recursive algorythm ViewableRecords like in your sample, the rows
get expanded, but I get the nullreference exception.

Why ?

I'd prefer using the ViewableRecords way I think is faster, but It doen't work for me.

In fact, event with GetRecordsInView, it does not event work (I believe it used to).

HI dialogues,

 What build are you using?

 Sincerely,.
 Matt
 Developer Support Engineer

I use IG WPF v11.2.

I put a sample test application where I Tried 2 different methods to expand the rows.

Both throw Nullrefexception.

In fact, it doe not work only if expand and sort are queued.

I joined a test project :

- The buttons "Expand and sort..." throw the exception

- If you try either "Expand Method 1" Or "expand Method 2" and then Push "Sort", It works !

I solved my issue like this. I don't know if there's a better way :

- I handle the layoutupdated event where I sort the rows

- Expand the grid (that will raise the event)

    Private Sub ExpandAndSort()
        AddHandler Me._xamDataGrid.LayoutUpdated, AddressOf _xamDataGrid_LayoutUpdated
        Me.ExpandAllRows(Me._xamDataGrid.ViewableRecords, True)
    End Sub
 
    Private Sub _xamDataGrid_LayoutUpdated(sender As System.Object, e As System.EventArgs) Handles _xamDataGrid.LayoutUpdated
        SetSort()
        RemoveHandler Me._xamDataGrid.LayoutUpdated, AddressOf _xamDataGrid_LayoutUpdated
    End Sub
 
    Private Sub ExpandAllRows(vrc As ViewableRecordCollection, expand As Boolean)
        For Each rec As Record In vrc
            rec.IsExpanded = expand
            If rec.HasChildren Then
                ExpandAllRows(rec.ViewableChildRecords, expand)
            End If
        Next
    End Sub

HI dialogues,

 Your solution is very good.

 Thanks for the update.

 Sincerely,
 Matt
 Developer Support Engineer