Combobox is it open or not!

I have开发者_如何学Python a problem to determinate if my combobox is open or not. I've seen the same topic but that solution : if(combobox.dropdown != null && combobx.dropdown.visible) doesn't work for me. It is always true. I can't find any component who is responsible for this such a simple operation. Thanks in advance.

ComboBoxes have 2 events that are thrown regarding the open/closing action. If you bind to those events with an addEventListener you can easily track its state:

close    Dispatched when the drop-down list is dismissed for any reason.    ComboBox
open     Dispatched when the user clicks the drop-down button to display the drop-down list.    ComboBox

API Reference: http://livedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/fl/controls/ComboBox.html