Thank you. I'm working through the solution for the expander icons for the parent rows. My grid has one child template. I ran into two issues with the cell formatting method:
1.In this part of the code
GridViewHierarchyRowInfo hierarchyRow = (GridViewHierarchyRowInfo)((GridViewDetailsRowInfo)cell.RowInfo).Owner;
i = 0; i < cell.PageViewElement.Items.Count; i++)
I get an error because cell.PageViewElement is null (sometimes). So I added a test: else if (cell != null && cell.PageViewElement != null) to get around that.
2. When the grid is first displayed, none of the parent rows have the expander element visible. I have to click on the cell for each row and the expander element will become visible if that row has child rows.
I'm working though it but if you have additional information I would like to know about that.