Class: TEgFireGridColumn
property SubTitle: string;An optional second line drawn under the title, in SubTitleFont
and SubTitleFontColor,
with the title’s horizontal alignment; empty (the default) draws
nothing. A unit of measure or a short hint under the caption are typical
uses. It may contain <var> markers.
It is always one line: word wrap and shrink-to-fit do not apply to
it. The title row does not grow for it: set the grid’s HeaderHeight
to make room for both lines. An OnBeforeDrawTitle
handler can change it for one title.