Class: TEgFireGrid
property SelectedColumn: Integer;Run time only. The column of the active cell, as an index into VisibleColumns
(0 = the leftmost visible column).
Setting it moves the active cell to that column of the active row and
scrolls it into view; the value is kept within the range of the visible
columns. When it changes, by the user or by code, OnColExit
fires for the column being left, then OnColEnter
for the new one.