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Currently Being Moderated error

Aug 29, 2013 11:21 PM

I've posted to the AIR forum but I'm beginning to think this is a Flex framework question. This sounds like the issue ( but I've hit a deadend trying to debug this thing.


I'm working on an app and I'm pretty stuck as the only code that comes up is below. I am trapping the escape key to stop a process. There are no Alerts in the message chain and I'm not quite sure where to go with the information I'm given, which occurs when I press the escape key.


TypeError: Error #1009: Cannot access a property or method of a null object reference.

  at mx.accessibility::AlertAccImpl/eventHandler()[E:\dev\4.y\frameworks\p rojects\mx\src\mx\accessibility\]



  at mx.core::UIComponent/dispatchEvent()[E:\dev\4.y\frameworks\projects\f ramework\src\mx\core\]

  at mx.controls.alertClasses::AlertForm/removeAlert()[E:\dev\4.y\framewor ks\projects\mx\src\mx\controls\alertClasses\]

  at mx.controls.alertClasses::AlertForm/keyDownHandler()[E:\dev\4.y\frame works\projects\mx\src\mx\controls\alertClasses\]


The framework code that it errors out at is the following. It says that systemManager is null. How can one make system manager null?

override protected function eventHandler(event:Event):void


  // Let AccImpl class handle the events

  // that all accessible UIComponents understand.



  const systemManager:ISystemManager = ISystemManager(master.parent);

  var titleBar:UIComponent;


  switch (event.type)


  case "close":


  titleBar = Alert(master).getTitleBar();






  Accessibility.sendEvent(titleBar,0,AccConst.EVENT_OBJECT_LOCATIONCHAN GE);

  Accessibility.sendEvent(titleBar,0,AccConst.EVENT_OBJECT_PARENTCHANGE );



  if (systemManager.stage.focus)

  Accessibility.sendEvent(systemManager.stage.focus,0,AccConst.EVENT_OB JECT_FOCUS);





  • Currently Being Moderated
    Aug 31, 2013 9:18 PM   in reply to John Hall

    There's an Alert somewhere.  Could be in a library.  Put a breakpoint on the and see who calls it.


    SystemManager might be null when an object is removed from the display list.


    Apache Flex has made some attempts to fix a similar error, but I'm not sure if it will fix your situation.  If you can come up with a simple test case, post it.

    Mark as:

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