Collapse/Expand Subtotal

After creating subtotal views, I change the visibility of specific fields based on the level and group.  How can I catch the expand/collapse button selected by the user in order to change the visiblity specific fields?

 

Thanks

The grid raises BeforeCollapse and AfterCollapse events that pass as a parameter the row being expanded or collapsed. I hope these provide the information you need to show/hide the cells.