Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. QApplication in library project
Forum Updated to NodeBB v4.3 + New Features

QApplication in library project

Scheduled Pinned Locked Moved Unsolved General and Desktop
libraryqapplicationqeventloop
17 Posts 3 Posters 4.7k Views 1 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • SlaneS Offline
    SlaneS Offline
    Slane
    wrote on last edited by Slane
    #7

    Ha... so I gonna to find another way... Without static method and object...

    But why we shouldn't create static object based on QObject ?

    EDIT : My bad... it's not static QObject based object but static ptr over QObject based object... it's the same case ?

    1 Reply Last reply
    0
    • SGaistS Offline
      SGaistS Offline
      SGaist
      Lifetime Qt Champion
      wrote on last edited by
      #8

      I didn't talk about static methods at all.

      QApplication does some initialisation. Your static QObject based classed would be created before QApplication and thus would be in an "uninitialised" state.

      No, static pointers are not concerned.

      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
      0
      • SlaneS Offline
        SlaneS Offline
        Slane
        wrote on last edited by
        #9

        I see... so I haven't static object... I don't find the problem...

        1 Reply Last reply
        0
        • SGaistS Offline
          SGaistS Offline
          SGaist
          Lifetime Qt Champion
          wrote on last edited by
          #10

          With the code you provided, there's nothing that can really be guessed except that you might have something wrong in your Database class.

          On an unrelated note, it seems you are not cleaning anything when destroying your CoreApp instance. At least from the code you posted.

          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
          0
          • SlaneS Offline
            SlaneS Offline
            Slane
            wrote on last edited by Slane
            #11

            I can't post all the code... they are no other thing like static object based on QObject who can throw this error ?

            @SGaist said in QApplication in library project:

            On an unrelated note, it seems you are not cleaning anything when destroying your CoreApp instance. At least from the code you posted.

            The database and thread aren't destroy by this way.

            jsulmJ 1 Reply Last reply
            0
            • SlaneS Slane

              I can't post all the code... they are no other thing like static object based on QObject who can throw this error ?

              @SGaist said in QApplication in library project:

              On an unrelated note, it seems you are not cleaning anything when destroying your CoreApp instance. At least from the code you posted.

              The database and thread aren't destroy by this way.

              jsulmJ Offline
              jsulmJ Offline
              jsulm
              Lifetime Qt Champion
              wrote on last edited by
              #12

              @Slane What is CoreApp?

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

              SlaneS 1 Reply Last reply
              0
              • jsulmJ jsulm

                @Slane What is CoreApp?

                SlaneS Offline
                SlaneS Offline
                Slane
                wrote on last edited by
                #13

                @jsulm CoreApp is the wrapper of all functionality in the DLL

                Currently :

                #include "coreapp_global.h"
                
                #include <QObject>
                
                class Database;
                
                class COREAPPSHARED_EXPORT CoreApp : public QObject
                {
                	Q_OBJECT
                
                	public:
                		static CoreApp* CoreAppInstance();
                		static void TerminateCoreApp();
                
                
                	private:
                		static CoreApp* instance;
                		CoreApp();
                		~CoreApp();
                
                		Database* database;
                		QThread* databaseThread;
                };
                
                1 Reply Last reply
                0
                • SGaistS Offline
                  SGaistS Offline
                  SGaist
                  Lifetime Qt Champion
                  wrote on last edited by
                  #14

                  What in Database since it's where you seem to have trouble ?

                  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
                  0
                  • SlaneS Offline
                    SlaneS Offline
                    Slane
                    wrote on last edited by Slane
                    #15

                    Minimal code that don't work :

                    In exe :

                    GUI.pro

                    QT       = core gui widgets
                    
                    TARGET = GUI
                    TEMPLATE = app
                    
                    LIBS += -LD:\Data\Code\Projet\build-CoreApp\debug -lCoreApp
                    
                    DEFINES += QT_DEPRECATED_WARNINGS
                    
                    SOURCES += \
                            main.cpp \
                        Core.cpp
                    
                    HEADERS += \
                        Core.h
                    

                    main.cpp

                    #include "Core.h"
                    
                    #include <QApplication>
                    
                    int main(int argc, char *argv[])
                    {
                    	QApplication a(argc, argv);
                    	Core core;
                    	return a.exec();
                    }
                    

                    core.h

                    #ifndef CORE_H
                    #define CORE_H
                    
                    
                    class Core
                    {
                    	public:
                    
                    		Core();
                    };
                    
                    #endif // CORE_H
                    

                    core.cpp

                    #include "Core.h"
                    #include "../CoreApp/CoreApp.h"
                    
                    Core::Core()
                    {
                    
                    	new CoreApp();
                    }
                    
                    void Core::start()
                    {
                    }
                    
                    Core::~Core()
                    {
                    	CoreApp::TerminateCoreApp();
                    }
                    

                    In dll

                    CoreApp.pro

                    QT       += sql core
                    
                    TARGET = CoreApp
                    TEMPLATE = lib
                    
                    DEFINES += QT_DEPRECATED_WARNINGS
                    
                    SOURCES += \
                            CoreApp.cpp \
                    
                    HEADERS += \
                            CoreApp.h \
                            CoreApp_global.h \ 
                    
                    unix {
                        target.path = /usr/lib
                        INSTALLS += target
                    }
                    

                    CoreApp.h

                    #ifndef COREAPP_H
                    #define COREAPP_H
                    
                    #include "coreapp_global.h"
                    
                    #include <QObject>
                    
                    class COREAPPSHARED_EXPORT CoreApp: public QObject
                    {
                    	Q_OBJECT
                    
                    	public:
                    		CoreApp();
                    	
                    	private:
                    		QThread* databaseThread;
                    
                    };
                    
                    #endif // COREAPP_H
                    

                    coreapp_gloable.h

                    #ifndef COREAPP_GLOBAL_H
                    #define COREAPP_GLOBAL_H
                    
                    #include <QtCore/qglobal.h>
                    
                    #if defined(COREAPP_LIBRARY)
                    #  define COREAPPSHARED_EXPORT Q_DECL_EXPORT
                    #else
                    #  define COREAPPSHARED_EXPORT Q_DECL_IMPORT
                    #endif
                    
                    #endif // COREAPP_GLOBAL_H
                    

                    CoreApp.cpp

                    #include "CoreApp.h"
                    
                    #include <QThread>
                    #include <QDebug>
                    
                    #include <QApplication>
                    
                    CoreApp::CoreApp()
                    {
                    	this->databaseThread = new QThread();
                    	this->databaseThread->start();
                    }
                    

                    I think the probleme don't come from the code...
                    (the code are handmodified)

                    1 Reply Last reply
                    0
                    • SGaistS Offline
                      SGaistS Offline
                      SGaist
                      Lifetime Qt Champion
                      wrote on last edited by
                      #16

                      Since you modified your code, what do you mean by "doesn't work" ?

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

                      SlaneS 1 Reply Last reply
                      0
                      • SGaistS SGaist

                        Since you modified your code, what do you mean by "doesn't work" ?

                        SlaneS Offline
                        SlaneS Offline
                        Slane
                        wrote on last edited by Slane
                        #17

                        @SGaist I wish mean throw this message : QEventLoop: Cannot be used without QApplication

                        But this problem is no more. I have delete the project and create un other without dll...
                        It's not the best solution but it's gona work.

                        1 Reply Last reply
                        0

                        • Login

                        • Login or register to search.
                        • First post
                          Last post
                        0
                        • Categories
                        • Recent
                        • Tags
                        • Popular
                        • Users
                        • Groups
                        • Search
                        • Get Qt Extensions
                        • Unsolved