问题
My Flex 3 application has some modal dialogs displayed via the PopUpManager, but there are times when I'd like other view components to know there is popup displayed. The PopUpManager doesn't have any method for actually checking the existence of popups. Is there any other way to detect this in flash/flex without writing my own global manager?
(also systemManager.popUpChildren.numChildren == 0 even when there's a modal popup)
Cheers.
回答1:
I think it depends on the way you are adding the popup, check the documentation :
http://livedocs.adobe.com/flex/3/langref/mx/managers/PopUpManager.html
create or add popup takes four parameters and fourth parameter is a child list
childList:String (default = null) — The child list in which to add the popup. One of PopUpManagerChildList.APPLICATION, PopUpManagerChildList.POPUP, or PopUpManagerChildList.PARENT (default).
So try adding all the popup's to a particular child-list and then play around with the size of the list.
回答2:
In case you have no control on the popups that are created (i.e. you've got a library component that creates popups and the component has not been made by you so you cannot modify it) you can still find all the popups in the application without adding them to a specific list. If interested in a different approach, you can check my blog post at http://www.devahead.com/blog/2009/12/getting-all-the-popups-in-a-flex-application/
回答3:
In flex 4.7, if a popup is already created, use isPopUp for the popup instance.
来源：https://stackoverflow.com/questions/1436754/flex-popupmanager-how-can-i-detect-the-existence-of-a-modal-popup