If you drop a FMX.TStringGrid onto a new FireMonkey form, the grid gets shown with a thin border.
If you drop a FMX.TTListView onto the form, there is no border.
Neither component seems to have a property for enabling/disabling the border, or setting the border colour or width.
I assume this is due to the cross-platform requirement, so how should it be done? Do I need to add a panel, then put the listview inside the panel? Or is it something to do with the style, as in needing a TStyleBook?
Yes, the TListView has no border. Firemonkey offers several ways to add a border to any visual control. For adding a simple border I would not try to change the styles.
In my opinion, the simplest solution is to put a rectangle from the palette (from Shapes) into the form.
Set in the rectangle the Stroke to the desired color and thickness.
As the next step, go to the structure-view in the designer and move the Listview as a child element into this rectangle. Change the Align property of the listview to Client.
To display the border-lines again, you must set all the values for Padding (bottom, left, right and top) of the rectangle to the value thickness of the rectangle stroke.
If you like you can also add a TShadowEffect on your rectangle or listview control.