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Event dispatching to background tasks

    Question

  • I did some further investigation about dispatching events to background tasks. My component usually uses the Dispatcher from the main window to trigger event notifications using a DispatchedHandler. Since in background tasks hosted by backgroundTaskHost.exe there is no window available so I cannot use the dispatcher. So I tried to invoke the registered event handlers directly. And it does seem to work indeed. Yet, I don't know why :)

    Another issue I am having is that triggering the background task from within the debugger does not perform in the same manner as when the system triggers it (ie timer after 15 minutes). When I trigger it myself the component that is called and events registered with, behaves strange and sometimes even terminates the host process.


    • Edited by phil_ke Tuesday, April 16, 2013 12:15 PM
    Tuesday, April 16, 2013 12:15 PM

All replies

  • Hi,

     

    There is no directly way to pass or return value between background task and Main UI.

     

    But you can store the value in  ApplicationData::Current->LocalSettings to do this.

     

    Best regards,

    Jesse


    Jesse Jiang
    MSDN Community Support | Feedback to us
    Develop and promote your apps in Windows Store
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    Wednesday, April 17, 2013 6:28 AM
  • there is no main UI in a background task. I am not sure what you trying to say here. Did you read my question and that it is indeed possible to pass values between a component and the background task?

    I mean how are the WinRT APIs which are all accessible from background tasks handle async operations or event notifications in background tasks?

    Wednesday, April 17, 2013 10:05 AM