ListBox.CellAction
From Xojo Documentation
Event
If a cell is editable, a CellAction event occurs when the user finishes editing a cell. Row and Column are zero-based.
Notes
“Finishing editing” is defined as exiting the cell after clicking in it. Tabbing out of the editable cell or clicking another cell triggers this event. Clicking a checkbox in a checkbox cell also qualifies as "finishing editing".
The user doesn't necessarily have to change the contents.
Examples
This code will display changes made to an editable cell when the user finishes editing (by either pressing return or switching to a different cell):
If column = 2 Then // Is this the editable column?
MessageBox("You entered: " + Me.Cell(row, column))
End If
MessageBox("You entered: " + Me.Cell(row, column))
End If
This event handler is also called when the user clicks a CheckBox cell: