Class: TEgColumn
property ImageIndex: Integer default -1;Default index into the grid’s Images for this
column’s data cells. -1 (the default) means “no image” -
the same convention OnBeforeDrawCell’s
own ImageIndex parameter already uses.
Read at the very start of cell drawing, before
OnBeforeDrawCell runs (grid handler, then this column’s),
both of which can still freely raise, lower, or clear whatever this
property seeded - it only supplies the starting value, it does not lock
it in. Unlike the nineteen live-tracking overrides (see TEgColumn), there is no
grid-wide equivalent to follow, since a default data-cell image is not
otherwise a concept that exists - the image is normally decided per
cell, dynamically, by the events.
Null, or content that failed to decode: the icon
is the cell’s only content, positioned the same way as on any other
column kind - horizontally by ImageAlignment,
vertically by CellVAlign
directly
(tlTop/tlCenter/tlBottom,
matching CellVAlign exactly).ShowImageOverGraphic
decides what happens. False (the default) fully suppresses
the icon - the decoded image is the cell’s only content, same as before
this property existed. True draws the icon as an overlay on
top of the image instead, at the same
ImageAlignment/CellVAlign position as the
fallback case above - there is no automatic adjustment to keep the icon
clear of the image, so the two may overlap. OnCellImageClick
fires correctly for a click on the overlay icon when
ShowImageOverGraphic is True, the same as for
the fallback icon above.See also TitleImageIndex
for the title cell, and ImageAlignment
to position the image.