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Receive event when pc wake up

  • Hi all,

    I am new with Qt. I know that this topic is old and probably it's solved but I don't find the solution. I am trying to implement a code that runs when the pc returns from suspend state. I've tried with WM_POWERBROADCAST but doesn't work.
    Attached my code:


      #include <QAbstractNativeEventFilter>
      #include <QObject>
      #include <QWidget>
      #include <windows.h>
     class windowsEvents : public QWidget, public QAbstractNativeEventFilter
                 virtual bool nativeEventFilter(const QByteArray &eventType, void *message, long *) Q_DECL_OVERRIDE;


    #include <winuser.h>
        RegisterSuspendResumeNotification((HANDLE)this, DEVICE_NOTIFY_WINDOW_HANDLE);
    bool windowsEvents::nativeEventFilter(const QByteArray &eventType, void *message, long *) {
        MSG *msg = static_cast<MSG *>(message);
        if (msg->message == WM_POWERBROADCAST) {
            if (msg->wParam == PBT_APMRESUMESUSPEND ) {
    return false;


    int main(int argc, char *argv[])
        QApplication app(argc, argv);
        windowsEvents devEventFilterObj;
       return app.exec();

    What is it wrong? What do i need to change?
    Thanks you

  • Lifetime Qt Champion

    Hi and welcome to devnet,

    You might want to check the implementation from this thread.

  • @SGaist

    Thanks for your reply. I am checking that thread and I can't find any difference with my code.

    In the thread it used rundll32.exe powrprof.dll, SetSuspendState 0,1,0 to sleep but I don't use those commands. I use the Windows key -> suspend. Could is it the problem?

    Thank you in advance.

  • Lifetime Qt Champion

    It is structured differently not mixing the event dispatcher with a widget.

    Did you test it ?
    What about yours when using SetSuspendState ?

  • @SGaist thanks for your answers.
    Finally, I found the solution. I didn't use the right handle for register solution.

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