Quote Originally Posted by Nouyana View Post
I should press F4 three times:
  • The first one it will be *ReasonInitialize
  • On the second one the drop-down list will be closed
  • And only after the third time I press F4 it will cause the *ReasonKeyboard.




Not "to close", but "to open it again". The same as with F4.



Nothing happens.



Yes, but we usually don't work that way with ComboBoxes.
Again.
It is necessary to have *Initialize reason in ComboBeforeDropDown. Because that's how to change behavior.
You can check .EditReason property in ComboBeforeDropDown to know if it is a Mouse or Keyboard action.