A Boolean expression that specifies whether the column is expanded / collapsed.
By default, the Expanded property is True. Use the Expanded
property to programmatically expand/collapse the columns. For instance, the
Expanded property on False, collapse the column, while the Expanded property
on True, expands the columns indicated by the ExpandColumns
property. The ExpandColumns property
specifies the columns to be shown/hidden when a column is expanded or
collapsed. The DisplayExpandButton
property indicates whether the +/- expanding/collapsing button is shown in the
column's header.