Thanks for your reply. Your workaround gave me an idea that is currently working.  It seemed to me that a new ''DataGridDetailDescription'' is created for each parent row, as opposed to using this object in a static way (no static methods).  So, I created my own workaround by changing my implementation of the DataGridDescription class ...

I had already implemented a DataGridDetailDescription.  It is working in the sense that I can expand any parent row and the child objects are displayed in child rows in a subgrid.  See the code below: (modified slightly to rename the names of my variables)   class ParentDetail : ...