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  • SGaistS SGaist

    So problem solved ? :)

    D Offline
    D Offline
    dejarked
    wrote on last edited by
    #17

    @SGaist The code actually compiles now! Thank you, the only issue left is I've replaced the code with

                behindlogin behindlogin;
                behindlogin.show();
                connClose();
    
    
    Which causes the window to open and them immediately close after
    1 Reply Last reply
    0
    • SGaistS Offline
      SGaistS Offline
      SGaist
      Lifetime Qt Champion
      wrote on last edited by
      #18

      If you have something like:

      {
          behindlogin behindlogin;
          behindlogin.show();
          connClose();
      } <- behindlogin is destroyed here
      

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

      D 1 Reply Last reply
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      • SGaistS SGaist

        If you have something like:

        {
            behindlogin behindlogin;
            behindlogin.show();
            connClose();
        } <- behindlogin is destroyed here
        
        D Offline
        D Offline
        dejarked
        wrote on last edited by
        #19

        @SGaist Right, so I've replaced it with

                        behindlogin *behindLogin;
        

        in the header file and then

                    behindLogin =new behindlogin(this);
                    behindLogin->show();
        

        in the main cpp file but it's saying that behindlogin does not name a type?

        JKSHJ 1 Reply Last reply
        0
        • SGaistS Offline
          SGaistS Offline
          SGaist
          Lifetime Qt Champion
          wrote on last edited by
          #20

          Is behindlogin a member variable of a class ?

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

          D 1 Reply Last reply
          1
          • SGaistS SGaist

            Is behindlogin a member variable of a class ?

            D Offline
            D Offline
            dejarked
            wrote on last edited by
            #21

            @SGaist Uh, honestly I'm not sure.. I'm very new to Qt and I've been following tutorials. Everything I've looked at makes it look like this should work but I can't figure out what I'm doing incorrectly.

            1 Reply Last reply
            0
            • D dejarked

              @SGaist Right, so I've replaced it with

                              behindlogin *behindLogin;
              

              in the header file and then

                          behindLogin =new behindlogin(this);
                          behindLogin->show();
              

              in the main cpp file but it's saying that behindlogin does not name a type?

              JKSHJ Offline
              JKSHJ Offline
              JKSH
              Moderators
              wrote on last edited by
              #22

              Hi,

              @dejarked said:

              in the main cpp file but it's saying that behindlogin does not name a type?

              That means you forgot to #include the header that defines the behindlogin.

              @dejarked said:

              @SGaist Uh, honestly I'm not sure.. I'm very new to Qt and I've been following tutorials. Everything I've looked at makes it look like this should work but I can't figure out what I'm doing incorrectly.

              Is your code exactly the same as what's in the tutorial?

              Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

              D 1 Reply Last reply
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              • JKSHJ JKSH

                Hi,

                @dejarked said:

                in the main cpp file but it's saying that behindlogin does not name a type?

                That means you forgot to #include the header that defines the behindlogin.

                @dejarked said:

                @SGaist Uh, honestly I'm not sure.. I'm very new to Qt and I've been following tutorials. Everything I've looked at makes it look like this should work but I can't figure out what I'm doing incorrectly.

                Is your code exactly the same as what's in the tutorial?

                D Offline
                D Offline
                dejarked
                wrote on last edited by
                #23

                @JKSH Hey, it is exactly the same as it is in the tutorial and the header file was the first thing I checked, behindlogin.h is included in my mainwindow.h which is where I'm trying to declare it.

                JKSHJ 1 Reply Last reply
                0
                • D dejarked

                  @JKSH Hey, it is exactly the same as it is in the tutorial and the header file was the first thing I checked, behindlogin.h is included in my mainwindow.h which is where I'm trying to declare it.

                  JKSHJ Offline
                  JKSHJ Offline
                  JKSH
                  Moderators
                  wrote on last edited by
                  #24

                  @dejarked said:

                  @JKSH Hey, it is exactly the same as it is in the tutorial and the header file was the first thing I checked, behindlogin.h is included in my mainwindow.h which is where I'm trying to declare it.

                  Can you post:

                  1. The contents of your .pro file
                  2. The contents of behindlogin.h
                  3. The contents of mainwindow.h ?

                  Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

                  1 Reply Last reply
                  1
                  • D Offline
                    D Offline
                    dejarked
                    wrote on last edited by
                    #25

                    Pro:

                    #
                    # Project created by QtCreator 2015-03-25T23:10:30
                    #
                    #-------------------------------------------------
                    
                    QT       += core gui sql
                    
                    greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
                    
                    TARGET = project
                    TEMPLATE = app
                    
                    
                    SOURCES += main.cpp\
                            mainwindow.cpp \
                        behindlogin.cpp \
                        offlinebehind.cpp \
                        savingwindow.cpp
                    
                    HEADERS  += mainwindow.h \
                        behindlogin.h \
                        offlinebehind.h \
                        savingwindow.h
                    
                    FORMS    += mainwindow.ui \
                        behindlogin.ui \
                        offlinebehind.ui \
                        savingwindow.ui
                    

                    behindlogin.h

                    #ifndef BEHINDLOGIN_H
                    #define BEHINDLOGIN_H
                    
                    #include <QMainWindow>
                    #include "mainwindow.h"
                    
                    namespace Ui {
                    class behindlogin;
                    }
                    
                    class behindlogin : public QMainWindow
                    {
                        Q_OBJECT
                    
                    public:
                        explicit behindlogin(QWidget *parent = 0);
                        ~behindlogin();
                    
                    private slots:
                        void on_actionExit_triggered();
                    
                        void on_actionNew_Data_triggered();
                    
                    private:
                        Ui::behindlogin *ui;
                    };
                    
                    #endif // BEHINDLOGIN_H
                    

                    mainwindow.h:

                    
                    #ifndef MAINWINDOW_H
                    #define MAINWINDOW_H
                    
                    #include "behindlogin.h"
                    #include <QMainWindow>
                    #include <QtSql>
                    #include <QtDebug>
                    #include <QFileInfo>
                    
                    
                    namespace Ui {
                    class MainWindow;
                    }
                    
                    class MainWindow : public QMainWindow
                    {
                        Q_OBJECT
                    
                    public:
                        QSqlDatabase mydb;
                        void  connClose(){
                            mydb.close();
                            mydb.removeDatabase(QSqlDatabase::defaultConnection);
                        }
                    
                        bool connOpen()
                        {
                    
                            mydb=QSqlDatabase::addDatabase("QSQLITE");
                            mydb.setDatabaseName("C:/Users/Jack/Desktop/ProjNEW/SQlite/dataset.db.sqlite");
                    
                            if(!mydb.open()){
                               qDebug()<<("Disconnected..");
                               return false;
                            }
                            else{
                                qDebug()<<("Connected..");
                                return true;
                               }
                    
                        }
                    
                    public:
                        explicit MainWindow(QWidget *parent = 0);
                        ~MainWindow();
                    
                    private slots:
                    
                        void on_LoginButton_clicked();
                    
                        void on_actionOpen_triggered();
                    
                        void on_actionExit_triggered();
                    
                    private:
                        Ui::MainWindow *ui;
                        behindlogin *behindLogin;
                    };
                    
                    #endif // MAINWINDOW_H
                    1 Reply Last reply
                    0
                    • JKSHJ Offline
                      JKSHJ Offline
                      JKSH
                      Moderators
                      wrote on last edited by
                      #26

                      Hmm... I can't see any mistakes in the code.

                      What's the full error message? Which line in which file is the error in?

                      Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

                      D 1 Reply Last reply
                      1
                      • JKSHJ JKSH

                        Hmm... I can't see any mistakes in the code.

                        What's the full error message? Which line in which file is the error in?

                        D Offline
                        D Offline
                        dejarked
                        wrote on last edited by
                        #27

                        @JKSH The full message is:

                        In file included from /behindlogin.h
                        from behindlogin.cpp
                        behindlogin does not name a type.

                        and the line of code it's flagging is:

                        
                            behindlogin *behindLogin;
                        1 Reply Last reply
                        0
                        • SGaistS Offline
                          SGaistS Offline
                          SGaist
                          Lifetime Qt Champion
                          wrote on last edited by
                          #28

                          Circular dependencies !

                          You are including mainwindow.h in behinglogin.h and behindlogin.h in mainwindow.h.

                          You can remove both includes: in behindlogin.h because you don't use it at all and in mainwindow.h because you can use forward declarations when declaring pointer data members. That also helps avoid including many headers to use your class.

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

                          D 1 Reply Last reply
                          3
                          • SGaistS SGaist

                            Circular dependencies !

                            You are including mainwindow.h in behinglogin.h and behindlogin.h in mainwindow.h.

                            You can remove both includes: in behindlogin.h because you don't use it at all and in mainwindow.h because you can use forward declarations when declaring pointer data members. That also helps avoid including many headers to use your class.

                            D Offline
                            D Offline
                            dejarked
                            wrote on last edited by
                            #29

                            @SGaist Ahhh thank you so much! It's all sorted now, I've added my final bits of code and no more errors!

                            Thanks @SGaist for all the help and thank you @JKSH as well!

                            1 Reply Last reply
                            0
                            • SGaistS Offline
                              SGaistS Offline
                              SGaist
                              Lifetime Qt Champion
                              wrote on last edited by
                              #30

                              Good !

                              You're welcome !

                              Don't forget to mark the thread as [solved] so other forum users may know a solution has been found :)

                              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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