Class: TEgDBGridEx
property OnCornerImageClick: TEgDBGridCornerImageClick;
Fired when a click - either mouse button - lands on the corner cell’s
image (see CornerImageIndex).
Button identifies which button was pressed. See TEgDBGridCornerImageClick.
The corner cell has no native click of its own, for either mouse
button - unlike OnCellImageClick
and OnTitleImageClick,
which each stand in for a native left-click equivalent, this event is a
plain addition. Only fires when CornerImageIndex is
actually set and the resulting image is visible; the corner cell itself
has no associated TColumn, so there is no column-level
counterpart.