DesktopListBox.AllowExpandableRows

From Xojo Documentation

Property (As Boolean )
aDesktopListBox.AllowExpandableRows = newBooleanValue
or
BooleanValue = aDesktopListBox.AllowExpandableRows

New in 2021r3

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.