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Thread: Queued Signal Slot connections

  1. #1
    Join Date
    May 2009
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    Default Queued Signal Slot connections

    Hello,

    I have a question concerning queued signal slot connections for interthread communication. With builtin Qt-types everything works fine. When I try to use some custom data classes as parameters it also works on Windows XP, but on Windows CE I get access violations when I emit the signal. I have registered my custom datatype with qRegisterMetaType and Q_DECLARE_METATYPE. Has anyone had experience with Qt 4.5.x and Windows CE here?

    Kind regards,
    Sebastian

  2. #2
    Join Date
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    Default Re: Queued Signal Slot connections

    signals and slots over thread use queued connection ..
    there trick is to use Q_DECLARE_METATYPE and qregisterMetaType

    * with queued connection , the parameter must be of types that are known to qt's meta object system .

    *because qt needs to copy the arguments to store them in event behind the scene

    if error came :
    QObject::connect:cannot queue argument with 'mtype'
    call QRegisterMetaType() to register the data type before connection is established ..

    have a good day
    "Behind every great fortune lies a crime" - Balzac

  3. #3
    Join Date
    May 2009
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    7
    Qt products
    Qt4 Qt/Embedded
    Platforms
    Windows

    Default Re: Queued Signal Slot connections

    Hi there.

    Thats exactly what I already did. And it works with Windows XP. The same code does not work for Windows CE.

    Any other suggestions?

    Cheers,
    Sebastian

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