Detecting TextInput changes on an editable ComboBox in Flex

If my ComboBox is editable how can I tell if a change event comes from a change to the TextInput or a change in the selectedIndex of the drop down?

Is there a way to check 开发者_如何转开发for this in the event object?

Check the selectedIndex property on the ComboBox--if your change happened in the dropdown list, this will be an index in the list; otherwise it will be -1.

See ComboBox.selectedIndex.