Hello,

After doing some research I found that when a field is resized it will fire the SizeChanged event. However, there is no built-in functionality to achieve this behavior and every time when some field is resized we have to loop through all levels and fields and to set their width manually. For big amount of data, it is extremely possible this action to lead to performance issues.

Hello,

My suggestion to achieve your requirement is first in the FieldLayoutInitialized event handler to set only the parent's fields Width property to Auto. In order to get this width and set it to the children fields width in the InitializeRecord event handler (which fires after the FieldLayoutInitialized), I'm using CellWidthResolved property. It's value is the actual width of cell because the value of the Width property is Auto, so if we try to get the parent Width value from there it will be Auto.

private void XamDataGrid1_InitializeRecord(object sender, Infragistics.Windows.DataPresenter.Events.InitializeRecordEventArgs e)
        {
            if (e.Record.FieldLayout.Key.ToString() == "ChildOrders")
            {
                foreach(var cell in ((Infragistics.Windows.DataPresenter.DataRecord)e.Record).Cells)
                {
                    cell.DataPresenter.MinWidth = 0;
                    cell.Field.Width = new FieldLength(((Infragistics.Windows.DataPresenter.ExpandableFieldRecord)e.Record.ParentRecord).Field.Owner.Fields[cell.Field.Index].CellWidthResolved);
                
                }
              
            }
        }

I modified the previous sample and attached it below. Please test it on your side and let me know if I may be of any further assistance.

Sincerely,

Teodosia Hristodorova

Associate Software Developer