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How Can i get array in another class

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  • A Offline
    A Offline
    anh_ph
    wrote on last edited by
    #18

    If class B is child of class A, then you can do sth like this in class B

    classA *clsA= dynamic_cast <classA*> (parent());
    clsA->funcToGetData();
    
    1 Reply Last reply
    0
    • D Offline
      D Offline
      dziko147
      wrote on last edited by
      #19

      @anh_ph the funcToGetData(); can be a slot wich get data from GUI elements ?

      And if classA isn't child od classB . How can i call it

      JonBJ A 2 Replies Last reply
      0
      • D dziko147

        @anh_ph the funcToGetData(); can be a slot wich get data from GUI elements ?

        And if classA isn't child od classB . How can i call it

        JonBJ Offline
        JonBJ Offline
        JonB
        wrote on last edited by JonB
        #20

        @dziko147 said in How Can i get array in another class:

        And if classA isn't child od classB . How can i call it

        The code you were shown attempts to cast the parent() to classA. If your classA instance is not related to you classB instance through its parent, then use whatever you have for the desired classA instance....

        I'm not sure but you seem not to understand the difference between a class and an instance (or object)? If that is the case I suggest you read up to understand, as this is vital in OO programming.

        1 Reply Last reply
        1
        • D Offline
          D Offline
          dziko147
          wrote on last edited by
          #21

          @JonB no i know the difference between instance and class .
          But honestly i have no idea what parent() mean .
          And if we say a classA is a child of classB we mean classA is inherited drom classB .

          Thank you

          jsulmJ 1 Reply Last reply
          0
          • D dziko147

            @JonB no i know the difference between instance and class .
            But honestly i have no idea what parent() mean .
            And if we say a classA is a child of classB we mean classA is inherited drom classB .

            Thank you

            jsulmJ Offline
            jsulmJ Offline
            jsulm
            Lifetime Qt Champion
            wrote on last edited by
            #22

            @dziko147 said in How Can i get array in another class:

            we mean classA is inherited drom classB

            No, we don't.
            See https://doc.qt.io/qt-5/objecttrees.html
            Parent/child is not about inheritance it is about relationships between QObject based classes.

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

            1 Reply Last reply
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            • D dziko147

              @anh_ph the funcToGetData(); can be a slot wich get data from GUI elements ?

              And if classA isn't child od classB . How can i call it

              A Offline
              A Offline
              anh_ph
              wrote on last edited by
              #23

              @dziko147 said in How Can i get array in another class:

              @anh_ph the funcToGetData(); can be a slot wich get data from GUI elements ?

              And if classA isn't child od classB . How can i call it

              If you want to get data from classA, you must get an exact object of it, which works with the data. If you can't do it, then try to apply singleton to classA.
              Btw, you can't get an array in another class, but you can get an array in an object of another class.

              1 Reply Last reply
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              • D Offline
                D Offline
                dziko147
                wrote on last edited by
                #24

                to resume what should i do to set data from GUI element in an array then get this array in another class .

                Btw I tried many solution but usually I get an empty array in the other class :)

                jsulmJ 1 Reply Last reply
                0
                • D dziko147

                  to resume what should i do to set data from GUI element in an array then get this array in another class .

                  Btw I tried many solution but usually I get an empty array in the other class :)

                  jsulmJ Offline
                  jsulmJ Offline
                  jsulm
                  Lifetime Qt Champion
                  wrote on last edited by
                  #25

                  @dziko147 said in How Can i get array in another class:

                  but usually I get an empty array in the other class

                  I guess that's because you have more than one instance of the class from which you get your array.
                  Please post your code. Passing data from one object to another is actually a trivial exercise.

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

                  1 Reply Last reply
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                  • D Offline
                    D Offline
                    dziko147
                    wrote on last edited by dziko147
                    #26

                    @jsulm

                    // classeA.h
                    std::array<QString,25> Inputs;
                    
                    // ClassA.cpp "UploadCSV"
                    void UploadCSV::on_parambtn_2_clicked()
                    {
                    
                        int compteur=0;
                        QString cell0;
                        QString cell3 ;
                        for(int i=0;i<ui->tablewidget->rowCount();i++){
                    
                            QTableWidgetItem *cell7 = ui->tablewidget->item(i,7);
                    
                            QVariant myData7 = cell7->data(Qt::DisplayRole);
                            if (myData7=="Core_meas"){
                                cell0  = ui->tablewidget->item(i,0)->text();
                                cell3 = ui->tablewidget->item(i,3)->text();
                                Inputs[compteur]=cell3;
                                qDebug() << "Inputs baby"<<Inputs[compteur] ;
                                compteur++;
                            }
                    
                        }
                    
                    
                    }
                    

                    //in classB.

                    UploadCSV *up;

                    //in classB.cpp

                    up=new UploadCSV();
                    for(size_t i=0;i<up.Inputs->size();i++){
                    qqDebug() << "this is data",up.Inputs[i]
                    
                    
                    jsulmJ Pl45m4P CP71C 3 Replies Last reply
                    0
                    • D dziko147

                      @jsulm

                      // classeA.h
                      std::array<QString,25> Inputs;
                      
                      // ClassA.cpp "UploadCSV"
                      void UploadCSV::on_parambtn_2_clicked()
                      {
                      
                          int compteur=0;
                          QString cell0;
                          QString cell3 ;
                          for(int i=0;i<ui->tablewidget->rowCount();i++){
                      
                              QTableWidgetItem *cell7 = ui->tablewidget->item(i,7);
                      
                              QVariant myData7 = cell7->data(Qt::DisplayRole);
                              if (myData7=="Core_meas"){
                                  cell0  = ui->tablewidget->item(i,0)->text();
                                  cell3 = ui->tablewidget->item(i,3)->text();
                                  Inputs[compteur]=cell3;
                                  qDebug() << "Inputs baby"<<Inputs[compteur] ;
                                  compteur++;
                              }
                      
                          }
                      
                      
                      }
                      

                      //in classB.

                      UploadCSV *up;

                      //in classB.cpp

                      up=new UploadCSV();
                      for(size_t i=0;i<up.Inputs->size();i++){
                      qqDebug() << "this is data",up.Inputs[i]
                      
                      
                      jsulmJ Offline
                      jsulmJ Offline
                      jsulm
                      Lifetime Qt Champion
                      wrote on last edited by
                      #27

                      @dziko147 Sorry, I fail to understand the code you posted.
                      What type is myclasseA? And why do you access Inputs from two different objects (up and myclasseA)?
                      It really looks like you have two different instances of UploadCSV...

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

                      1 Reply Last reply
                      0
                      • D dziko147

                        @jsulm

                        // classeA.h
                        std::array<QString,25> Inputs;
                        
                        // ClassA.cpp "UploadCSV"
                        void UploadCSV::on_parambtn_2_clicked()
                        {
                        
                            int compteur=0;
                            QString cell0;
                            QString cell3 ;
                            for(int i=0;i<ui->tablewidget->rowCount();i++){
                        
                                QTableWidgetItem *cell7 = ui->tablewidget->item(i,7);
                        
                                QVariant myData7 = cell7->data(Qt::DisplayRole);
                                if (myData7=="Core_meas"){
                                    cell0  = ui->tablewidget->item(i,0)->text();
                                    cell3 = ui->tablewidget->item(i,3)->text();
                                    Inputs[compteur]=cell3;
                                    qDebug() << "Inputs baby"<<Inputs[compteur] ;
                                    compteur++;
                                }
                        
                            }
                        
                        
                        }
                        

                        //in classB.

                        UploadCSV *up;

                        //in classB.cpp

                        up=new UploadCSV();
                        for(size_t i=0;i<up.Inputs->size();i++){
                        qqDebug() << "this is data",up.Inputs[i]
                        
                        
                        Pl45m4P Offline
                        Pl45m4P Offline
                        Pl45m4
                        wrote on last edited by Pl45m4
                        #28

                        @dziko147 said in How Can i get array in another class:

                        ,myclasseA.Inputs[i]

                        Why do you have myClasseA there, when the object is up
                        Try up.Inputs[i]

                        (Corrected, thx @jsulm )


                        If debugging is the process of removing software bugs, then programming must be the process of putting them in.

                        ~E. W. Dijkstra

                        jsulmJ 1 Reply Last reply
                        0
                        • Pl45m4P Pl45m4

                          @dziko147 said in How Can i get array in another class:

                          ,myclasseA.Inputs[i]

                          Why do you have myClasseA there, when the object is up
                          Try up.Inputs[i]

                          (Corrected, thx @jsulm )

                          jsulmJ Offline
                          jsulmJ Offline
                          jsulm
                          Lifetime Qt Champion
                          wrote on last edited by
                          #29

                          @Pl45m4 said in How Can i get array in another class:

                          when the object is UploadCSV

                          UploadCSV seems to be the class, not object

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

                          1 Reply Last reply
                          0
                          • D Offline
                            D Offline
                            dziko147
                            wrote on last edited by
                            #30

                            @jsulm sorry I edited the code .

                            I gave the expamle of classA and ClassB to be clearer .

                            ClassA (UploadCSV ) is a Qwidget : Qdialog

                            ClassB (Backend) is QObject .

                            jsulmJ 1 Reply Last reply
                            0
                            • D dziko147

                              @jsulm

                              // classeA.h
                              std::array<QString,25> Inputs;
                              
                              // ClassA.cpp "UploadCSV"
                              void UploadCSV::on_parambtn_2_clicked()
                              {
                              
                                  int compteur=0;
                                  QString cell0;
                                  QString cell3 ;
                                  for(int i=0;i<ui->tablewidget->rowCount();i++){
                              
                                      QTableWidgetItem *cell7 = ui->tablewidget->item(i,7);
                              
                                      QVariant myData7 = cell7->data(Qt::DisplayRole);
                                      if (myData7=="Core_meas"){
                                          cell0  = ui->tablewidget->item(i,0)->text();
                                          cell3 = ui->tablewidget->item(i,3)->text();
                                          Inputs[compteur]=cell3;
                                          qDebug() << "Inputs baby"<<Inputs[compteur] ;
                                          compteur++;
                                      }
                              
                                  }
                              
                              
                              }
                              

                              //in classB.

                              UploadCSV *up;

                              //in classB.cpp

                              up=new UploadCSV();
                              for(size_t i=0;i<up.Inputs->size();i++){
                              qqDebug() << "this is data",up.Inputs[i]
                              
                              
                              CP71C Offline
                              CP71C Offline
                              CP71
                              wrote on last edited by
                              #31

                              @dziko147 said in How Can i get array in another class:

                              up=new UploadCSV();
                              for(size_t i=0;i<up.Inputs->size();i++){
                              qqDebug() << "this is data",up.Inputs[i]

                              Sorry, who calls the on_parambtn_2_clicked() function?

                              1 Reply Last reply
                              1
                              • D dziko147

                                @jsulm sorry I edited the code .

                                I gave the expamle of classA and ClassB to be clearer .

                                ClassA (UploadCSV ) is a Qwidget : Qdialog

                                ClassB (Backend) is QObject .

                                jsulmJ Offline
                                jsulmJ Offline
                                jsulm
                                Lifetime Qt Champion
                                wrote on last edited by
                                #32

                                @dziko147 Is this your real code:

                                up=new UploadCSV();
                                for(size_t i=0;i<up.Inputs->size();i++){
                                qqDebug() << "this is data",up.Inputs[i]
                                

                                ?
                                Because Items is filled when UploadCSV::on_parambtn_2_clicked() is called (at least according to code you posted). But you're printing Inputs just after creating UploadCSV instance (up)! So why should there be anything in Inputs?

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

                                D 1 Reply Last reply
                                3
                                • D Offline
                                  D Offline
                                  dziko147
                                  wrote on last edited by
                                  #33

                                  @CP71 it's called in UploadCSV class (classA) .

                                  and inside this function I set data in Inputs[] .

                                  jsulmJ 1 Reply Last reply
                                  0
                                  • D dziko147

                                    @CP71 it's called in UploadCSV class (classA) .

                                    and inside this function I set data in Inputs[] .

                                    jsulmJ Offline
                                    jsulmJ Offline
                                    jsulm
                                    Lifetime Qt Champion
                                    wrote on last edited by jsulm
                                    #34

                                    @dziko147 said in How Can i get array in another class:

                                    it's called in UploadCSV class (classA) .

                                    Where exactly?! And what is classA?! This all is really confusing!
                                    up != classA

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

                                    D 1 Reply Last reply
                                    1
                                    • jsulmJ jsulm

                                      @dziko147 Is this your real code:

                                      up=new UploadCSV();
                                      for(size_t i=0;i<up.Inputs->size();i++){
                                      qqDebug() << "this is data",up.Inputs[i]
                                      

                                      ?
                                      Because Items is filled when UploadCSV::on_parambtn_2_clicked() is called (at least according to code you posted). But you're printing Inputs just after creating UploadCSV instance (up)! So why should there be anything in Inputs?

                                      D Offline
                                      D Offline
                                      dziko147
                                      wrote on last edited by
                                      #35

                                      @jsulm yes i understand you . So can you suggest a way to do this correctly ?

                                      jsulmJ SGaistS 2 Replies Last reply
                                      0
                                      • D dziko147

                                        @jsulm yes i understand you . So can you suggest a way to do this correctly ?

                                        jsulmJ Offline
                                        jsulmJ Offline
                                        jsulm
                                        Lifetime Qt Champion
                                        wrote on last edited by
                                        #36

                                        @dziko147 Yes, I can: use one instance of the class instead of two...

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

                                        1 Reply Last reply
                                        2
                                        • D dziko147

                                          @jsulm yes i understand you . So can you suggest a way to do this correctly ?

                                          SGaistS Offline
                                          SGaistS Offline
                                          SGaist
                                          Lifetime Qt Champion
                                          wrote on last edited by
                                          #37

                                          @dziko147 said in How Can i get array in another class:

                                          @jsulm yes i understand you . So can you suggest a way to do this correctly ?

                                          Something like it was explained in your other thread ?

                                          Interested in AI ? www.idiap.ch
                                          Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                                          1 Reply Last reply
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