Maybe with a line just containing: LB.SetFocus() ?
I would not do this in an Opening Event. Better in a Timer which runs a few milliseconds after the window/container has opened. Just to make sure all objects are drawn, before i set the focus.
Beware on a Mac:
On the Mac you need Full Keyboard Access turned on in System Preferences (Keyboard->Shortcuts) in order to manually set focus to non-text controls.
Did you actually try that? It doesn’t appear to work that way now, and I don’t remember a time when it ever did. Disabling the focus ring will not prevent cell editing. Can you upload a sample that shows that being the case? I’d consider that a bug in Xojo.
I don’t believe you can have cell-specific focus without some additional work tracking and drawing the cell to be focused, especially by using EditCellAt. Unless I’m misunderstanding the problem. AllowFocusRing just turns off drawing of the focus ring, it doesn’t switch the ListBox to cell-specific focus.
EDIT: Re-reading the thread, Emile just wants to set the focus to the ListBox when opening, which doesn’t appear to be happening. Everything below post 5 is off-topic, misleading, and probably not helpful to him.