I'd like to click in a grid cell and be able to edit with a tree control.
I don't even know if that's possible.
Do you mean a grid cell where the user can drop down a tree and select something from that tree?
Or do you want a tree or a grid inside a grid cell?
Or something else?
A grid cell where the user can drop down a tree and select something from that tree.
A similar question is asked and answered here along with a small sample project demonstrating how to do this:
https://es.infragistics.com/community/forums/f/ultimate-ui-for-windows-forms/92414/in-an-ultrawingrid-want-to-have-a-dropdown-combo-box-column-that-drops-down-into-tree-controlPlease let us know if you have any follow-up questions.