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communicate data between two windows

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  • AlbatorA Albator

    I try getter/setter :

    in my first windows second_p2

    // seconde_p2.h
    
        //getter
        int get_c() const{return c;}
        //setter
        void set_c(int val);
    
    protected :
        int c;
    
    // seconde_p2.cpp
    seconde_p2::seconde_p2(QWidget *parent) :
        QMainWindow(parent),
        ui(new Ui::seconde_p2)
    {
        ui->setupUi(this);
    
        c=3;
    
    
    }
    

    yes for this example setter is useless and in my seconde page alias seconde_p3 i have :

    // seconde_p3.cpp
    
    seconde_p3::seconde_p3(QWidget *parent) :
        QMainWindow(parent),
        ui(new Ui::seconde_p3)
    {
        ui->setupUi(this);
    
    
    
    seconde_p2* test = new seconde_p2();
    test->get_c();
    qDebug()<< test;
    
    
    
    }
    

    i have 0 error but ! in the console i can look this :
    seconde_p2(0x1bf26bf8, name="seconde_p2")

    and it's not my c=3 :(

    B Offline
    B Offline
    Bonnie
    wrote on last edited by Bonnie
    #6

    @Albator said in communicate data between two windows:

    i have 0 error but ! in the console i can look this :
    seconde_p2(0x1bf26bf8, name="seconde_p2")

    and it's not my c=3 :(

    [EDITED]
    Sorry, didn't understand your code until now...

    qDebug()<< test->get_c();
    

    That should output a "3"

    1 Reply Last reply
    2
    • AlbatorA Offline
      AlbatorA Offline
      Albator
      wrote on last edited by
      #7

      yes it's exact ! thanks all for your help ! :)))

      1 Reply Last reply
      0
      • AlbatorA Offline
        AlbatorA Offline
        Albator
        wrote on last edited by Albator
        #8

        i have a little problem, for a int it's okay but to make a getter with a qvector<double> it doesn't work.

        seconde_p2.h
         //getter
            int get_c() const{return c;}
            QVector<double> get_vector() const{return fer;}
            //setter
            //void set_c(int val);
        
        protected :
            int c=6;
            QVector<double> fer;
        
        // seconde_p2.cpp
        seconde_p2::seconde_p2(QWidget *parent) :
            QMainWindow(parent),
            ui(new Ui::seconde_p2)
        {
            ui->setupUi(this);
        
            c=3;
            fer={ 1, 2, 3, 4, 5, 6, 7 };
        
        
        }
        

        and in the seconde_p3.cpp

        seconde_p3::seconde_p3(QWidget *parent) :
            QMainWindow(parent),
            ui(new Ui::seconde_p3)
        {
            ui->setupUi(this);
        
        seconde_p2* test = new seconde_p2();
        seconde_p2* test1 = new seconde_p2();
        
        test->get_vector();
        qDebug()<<"qvector<double> display"<< test->get_vector();
        
        test1->get_c();
        qDebug()<<"int display"<< test1->get_c();
        
        
        }
        

        in the console :

        qvector<double> display QVector() // why he is empty ?
        int display 3

        1 Reply Last reply
        0
        • AlbatorA Offline
          AlbatorA Offline
          Albator
          wrote on last edited by
          #9
          This post is deleted!
          1 Reply Last reply
          0
          • mrjjM Offline
            mrjjM Offline
            mrjj
            Lifetime Qt Champion
            wrote on last edited by
            #10

            Hi
            Should work as you put value in the vector, in the constructor.

            what does test->get_vector();
            do ?

            maybe you return empty list there ?

            1 Reply Last reply
            0
            • AlbatorA Offline
              AlbatorA Offline
              Albator
              wrote on last edited by
              #11

              @Albator said in communicate data between two windows:

              QVector<double> get_vector() const{return fer;}

              and fer is not empty, it works for c ...

              1 Reply Last reply
              0
              • Q Offline
                Q Offline
                Q139
                wrote on last edited by
                #12

                Is it wrong to use global window pointers and access setters getters via pointer instead of signals&slots?

                1 Reply Last reply
                0
                • AlbatorA Offline
                  AlbatorA Offline
                  Albator
                  wrote on last edited by
                  #13

                  i want use getter in first but if i have not the choice maybe i will change my solution, it works for c so it should work for the qvector

                  mrjjM 1 Reply Last reply
                  0
                  • AlbatorA Albator

                    i want use getter in first but if i have not the choice maybe i will change my solution, it works for c so it should work for the qvector

                    mrjjM Offline
                    mrjjM Offline
                    mrjj
                    Lifetime Qt Champion
                    wrote on last edited by
                    #14

                    @Albator
                    yes must also work for Qvector same way as int.

                    AlbatorA 1 Reply Last reply
                    0
                    • mrjjM mrjj

                      @Albator
                      yes must also work for Qvector same way as int.

                      AlbatorA Offline
                      AlbatorA Offline
                      Albator
                      wrote on last edited by
                      #15

                      @mrjj
                      that's what I think, but who knows where the pangolin is that's standing in the way of my code?

                      mrjjM 1 Reply Last reply
                      0
                      • AlbatorA Albator

                        @mrjj
                        that's what I think, but who knows where the pangolin is that's standing in the way of my code?

                        mrjjM Offline
                        mrjjM Offline
                        mrjj
                        Lifetime Qt Champion
                        wrote on last edited by
                        #16

                        @Albator
                        so while it returns empty list and the same time in same code and
                        in same run, it can return 3 for c ?
                        it seems impossible :)

                        AlbatorA 1 Reply Last reply
                        1
                        • mrjjM mrjj

                          @Albator
                          so while it returns empty list and the same time in same code and
                          in same run, it can return 3 for c ?
                          it seems impossible :)

                          AlbatorA Offline
                          AlbatorA Offline
                          Albator
                          wrote on last edited by
                          #17

                          @mrjj
                          in first i put my value :

                          seconde_p2::seconde_p2(QWidget *parent) :
                              QMainWindow(parent),
                              ui(new Ui::seconde_p2)
                          {
                              ui->setupUi(this);
                          
                              c=3;
                              fer={ 1, 2, 3, 4, 5, 6, 7 };
                              qDebug() << fer;
                          
                          
                          }
                          

                          and in second i have a button who call the other windows :

                          void seconde_p2::on_page3_clicked()
                          {
                              p3 = new seconde_p3(this);
                              p3->show();
                          }
                          

                          and for the final in the second_p3.cpp (my other window), i use my getter and display :

                          seconde_p3::seconde_p3(QWidget *parent) :
                              QMainWindow(parent),
                              ui(new Ui::seconde_p3)
                          {
                              ui->setupUi(this);
                          
                          seconde_p2* test = new seconde_p2();
                          seconde_p2* test1 = new seconde_p2();
                          
                          test->get_data1();
                          qDebug()<<"qvector<double> display"<< test->get_data1();
                          
                          test1->get_c();
                          qDebug()<<"int display"<< test1->get_c();
                          
                          
                          }
                          

                          and tadaaaa : c is displayed correctly and fer is empty
                          my conclusion ? it's a sad day :(

                          1 Reply Last reply
                          0
                          • Christian EhrlicherC Offline
                            Christian EhrlicherC Offline
                            Christian Ehrlicher
                            Lifetime Qt Champion
                            wrote on last edited by
                            #18

                            @Albator said in communicate data between two windows:

                            seconde_p2* test = new seconde_p2();
                            seconde_p2* test1 = new seconde_p2();

                            C++ basics - this are new local instances - it won't help at all. You have to pass the pointer from the other object to this class. This is basic c++ stuff - programming with Qt without this basic knowledge will not work.

                            Qt Online Installer direct download: https://download.qt.io/official_releases/online_installers/
                            Visit the Qt Academy at https://academy.qt.io/catalog

                            AlbatorA 1 Reply Last reply
                            3
                            • Christian EhrlicherC Christian Ehrlicher

                              @Albator said in communicate data between two windows:

                              seconde_p2* test = new seconde_p2();
                              seconde_p2* test1 = new seconde_p2();

                              C++ basics - this are new local instances - it won't help at all. You have to pass the pointer from the other object to this class. This is basic c++ stuff - programming with Qt without this basic knowledge will not work.

                              AlbatorA Offline
                              AlbatorA Offline
                              Albator
                              wrote on last edited by
                              #19

                              @Christian-Ehrlicher
                              excuse me I try and thanks to your advices I advance and yes sometimes I miss my bases :)

                              1 Reply Last reply
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