ListBox.AllowExpandableRows
From Xojo Documentation
Property (As Boolean )
aListBox.AllowExpandableRows = newBooleanValue
or
BooleanValue = aListBox.AllowExpandableRows
New in 2019r2
Supported for all project types and targets.
or
BooleanValue = aListBox.AllowExpandableRows
New in 2019r2
Supported for all project types and targets.
Allows for disclosure triangles for rows added via the AddExpandableRow method.
Notes
On Windows, plus and minus signs are used instead of disclosure triangles.