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communicate data between two windows

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  • mrjjM Offline
    mrjjM Offline
    mrjj
    Lifetime Qt Champion
    wrote on last edited by
    #3

    Hi
    One way is to give it to the window when you create it.
    Change its constructor to accept extra parameter
    and give it to it when constructed.

    int c= xxxx
    seconde_p3 * win3 = new seconde_p3(this, c):
    win3->show();

    1 Reply Last reply
    2
    • AlbatorA Offline
      AlbatorA Offline
      Albator
      wrote on last edited by
      #4
      This post is deleted!
      1 Reply Last reply
      0
      • AlbatorA Offline
        AlbatorA Offline
        Albator
        wrote on last edited by
        #5

        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 1 Reply Last reply
        0
        • 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"

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          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

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              0
              • AlbatorA Offline
                AlbatorA Offline
                Albator
                wrote on last edited by
                #9
                This post is deleted!
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                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 ?

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                  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 ...

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                    0
                    • ? Offline
                      ? Offline
                      A Former User
                      wrote on last edited by
                      #12

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

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                      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 :(

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                                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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