Fired before the built-in combobox drops down.
Public Event ComboDropDown As CellEventHandler
Grid Object
The following parameters are available:
| Parameter | Description |
| Row | Row number of the cell containing the combo box. |
| Col | Column number of the cell containing the combo box. |
In this event,you may set or retrieve the contents of the editor using the EditText property and manipulate the contents of the editor using the EditSelectionStart, EditSelectionLength, and EditSelectedText properties.