Process a wxEVT_COMMAND_COMBOBOX_DROPDOWN event, which is generated
when the list box part of the combo box is shown (drops down).
Notice that this event is currently only supported by wxMSW and
wxGTK with GTK+ 2.10 or later.
Process a wxEVT_COMMAND_COMBOBOX_DROPDOWN event, which is generated
when the list box part of the combo box is shown (drops down).
Notice that this event is currently only supported by wxMSW and
wxGTK with GTK+ 2.10 or later.