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Forum Update on Monday, May 27th 2025

Connect Signal to boolean variable

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  • Y Offline
    Y Offline
    yczo
    wrote on 18 May 2016, 15:15 last edited by
    #1

    That is my idea (mnC is an object in a paralel thread)

    connect(mnC,SIGNAL(connected(bool)),this->isConnected,SLOT(append(bool) ,Qt::QueuedConnection);

    Please can somebody help me to make a direct connection between the boolean "isConnected" in MainWindow and the signal "connected" in thread?

    Thanks in advance

    M J P 3 Replies Last reply 18 May 2016, 15:31
    0
    • Y yczo
      18 May 2016, 15:15

      That is my idea (mnC is an object in a paralel thread)

      connect(mnC,SIGNAL(connected(bool)),this->isConnected,SLOT(append(bool) ,Qt::QueuedConnection);

      Please can somebody help me to make a direct connection between the boolean "isConnected" in MainWindow and the signal "connected" in thread?

      Thanks in advance

      M Offline
      M Offline
      MartinD
      wrote on 18 May 2016, 15:31 last edited by MartinD
      #2

      @yczo Why to complicate things? Just connect connected signal to a slot in "this" object which will set isConnected to the value passed via connected signal.

      1 Reply Last reply
      2
      • Y yczo
        18 May 2016, 15:15

        That is my idea (mnC is an object in a paralel thread)

        connect(mnC,SIGNAL(connected(bool)),this->isConnected,SLOT(append(bool) ,Qt::QueuedConnection);

        Please can somebody help me to make a direct connection between the boolean "isConnected" in MainWindow and the signal "connected" in thread?

        Thanks in advance

        J Offline
        J Offline
        jsulm
        Lifetime Qt Champion
        wrote on 19 May 2016, 04:59 last edited by
        #3

        @yczo You cannot connect a signal to a variable. Signals are connected to slots (which are C++ methods).
        As @MartinD said add a slot with a bool parameter to your class and connect the signal to that slot. In the slot you then set your variable.

        https://forum.qt.io/topic/113070/qt-code-of-conduct

        1 Reply Last reply
        3
        • Y Offline
          Y Offline
          yczo
          wrote on 23 May 2016, 11:55 last edited by
          #4

          Thank you very much all

          1 Reply Last reply
          1
          • Y yczo
            18 May 2016, 15:15

            That is my idea (mnC is an object in a paralel thread)

            connect(mnC,SIGNAL(connected(bool)),this->isConnected,SLOT(append(bool) ,Qt::QueuedConnection);

            Please can somebody help me to make a direct connection between the boolean "isConnected" in MainWindow and the signal "connected" in thread?

            Thanks in advance

            P Offline
            P Offline
            p3c0
            Moderators
            wrote on 23 May 2016, 12:07 last edited by
            #5

            @yczo Well you can use C++11 features. Instead of creating a slot you can do:

            connect(mnC, &MNCClass::connected, [=](const bool status){
                 isConnected = status;
            });
            

            P.S: I don't know name of class which contains connected so used MNCClass. Change it to your actual classname.

            157

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            18 May 2016, 15:15

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