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How can I use a DLL, in VS, without needing to load the moc files from the DLL?

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  • AEROLASER_THAA AEROLASER_THA

    @kshegunov

    #ifndef AECREATORMENU_H
    #define AECREATORMENU_H
    
    #include "aebasecreatormenu.h"
    
    template <class T> class AECREATOR_EXPORT  AeCreatorMenu : public AeBaseCreatorMenu
    {
    public:
    	explicit AeCreatorMenu(const QString &creatorName, QObject *parent = 0)	: AeBaseCreatorMenu(creatorName, parent){};
    	~AeCreatorMenu(){};
    
    	QMenu* createMenu(QWidget *parent = 0)
    	{
    		return static_cast<QMenu*>(new T(parent));
    	}
    
    private:
    	Q_DISABLE_COPY(AeCreatorMenu);
    };
    
    #endif // AECREATORMENU_H
    

    [Added code tags ~kshegunov]

    AEROLASER_THAA Offline
    AEROLASER_THAA Offline
    AEROLASER_THA
    wrote on last edited by
    #12

    @AEROLASER_THA
    Dear Kshegunov;
    The problem is with any class, regardless of whether it is abstract or not. With any simple project and class.

    If I am actually declaring AECREATOR_LIB, in the project AeCreator_test.exe

    Preprocessor:
    UNICODE; WIN64; QT_DLL; QT_NO_DEBUG; NDEBUG; QT_CORE_LIB; QT_GUI_LIB; QT_WIDGETS_LIB; AECREATOR_LIB;% (PreprocessorDefinitions)

    mrjjM kshegunovK 2 Replies Last reply
    0
    • AEROLASER_THAA AEROLASER_THA

      @AEROLASER_THA
      Dear Kshegunov;
      The problem is with any class, regardless of whether it is abstract or not. With any simple project and class.

      If I am actually declaring AECREATOR_LIB, in the project AeCreator_test.exe

      Preprocessor:
      UNICODE; WIN64; QT_DLL; QT_NO_DEBUG; NDEBUG; QT_CORE_LIB; QT_GUI_LIB; QT_WIDGETS_LIB; AECREATOR_LIB;% (PreprocessorDefinitions)

      mrjjM Offline
      mrjjM Offline
      mrjj
      Lifetime Qt Champion
      wrote on last edited by
      #13

      @AEROLASER_THA
      Hi
      Did you try something simple like
      https://wiki.qt.io/How_to_create_a_library_with_Qt_and_use_it_in_an_application

      It shows the step both for the DLL and for the host app.

      AEROLASER_THAA 1 Reply Last reply
      1
      • AEROLASER_THAA AEROLASER_THA

        @AEROLASER_THA
        Dear Kshegunov;
        The problem is with any class, regardless of whether it is abstract or not. With any simple project and class.

        If I am actually declaring AECREATOR_LIB, in the project AeCreator_test.exe

        Preprocessor:
        UNICODE; WIN64; QT_DLL; QT_NO_DEBUG; NDEBUG; QT_CORE_LIB; QT_GUI_LIB; QT_WIDGETS_LIB; AECREATOR_LIB;% (PreprocessorDefinitions)

        kshegunovK Offline
        kshegunovK Offline
        kshegunov
        Moderators
        wrote on last edited by
        #14

        @AEROLASER_THA said in How can I use a DLL, in VS, without needing to load the moc files from the DLL?:

        If I am actually declaring AECREATOR_LIB, in the project AeCreator_test.exe

        Which I said you shouldn't! You should define that only when building the library, not when using the library, otherwise it will not expand to __declspec(dllimport) which is mandatory on windows.

        Read and abide by the Qt Code of Conduct

        1 Reply Last reply
        2
        • mrjjM mrjj

          @AEROLASER_THA
          Hi
          Did you try something simple like
          https://wiki.qt.io/How_to_create_a_library_with_Qt_and_use_it_in_an_application

          It shows the step both for the DLL and for the host app.

          AEROLASER_THAA Offline
          AEROLASER_THAA Offline
          AEROLASER_THA
          wrote on last edited by kshegunov
          #15

          @mrjj

          //DLL test

          //test.h

          #include "test_global.h"
          
          #include <QtWidgets/QWidget>
          
          class TEST_EXPORT Widget : public QWidget
          {
          	Q_OBJECT
          
          public:
              Widget();
          };
          

          //test_global.h

          #include <QtCore/qglobal.h>
          
          #ifndef QT_STATIC
          # if defined(TEST_LIB)
          #  define TEST_EXPORT Q_DECL_EXPORT
          # else
          #  define TEST_EXPORT Q_DECL_IMPORT
          # endif
          #else
          # define TEST_EXPORT
          #endif
          
          //test.cpp
          #include "test.h"
          
          Widget::Widget()
          {
          
          }
          

          //PROJECT

          #include <QtWidgets/QApplication>
          
          #include "test.h"
          
          int main(int argc, char *argv[])
          {
              QApplication a(argc, argv);
          	Widget w;
          	w.resize(100, 100);
          	w.show();
          	return a.exec();
          }
          

          //CONFIFGURATION
          Additional Inclusion Directories;
          .\GeneratedFiles;.;$(QTDIR)\include;.\GeneratedFiles$(ConfigurationName);$(QTDIR)\include\QtCore;$(QTDIR)\include\QtGui;$(QTDIR)\include\QtWidgets;..\test;..\test\GeneratedFiles$(ConfigurationName);%(AdditionalIncludeDirectories)

          Preprocessor;
          UNICODE;WIN32;WIN64;QT_DLL;QT_CORE_LIB;QT_GUI_LIB;QT_WIDGETS_LIB;TEST_LIB;%(PreprocessorDefinitions)

          Directory of additional libraries;
          $(QTDIR)\lib;$(SolutionDir)$(Platform)$(Configuration);%(AdditionalLibraryDirectories)
          Linker;
          qtmaind.lib;Qt5Cored.lib;Qt5Guid.lib;Qt5Widgetsd.lib;test.lib;%(AdditionalDependencies)

          If I do not load the moc_test.cpp file generated with the DLL, the following error occurs in the exe project manually;

          main.obj : error LNK2001: símbolo externo "public: static struct QMetaObject const Widget::staticMetaObject" (?staticMetaObject@Widget@@2UQMetaObject@@B) sin resolver
          1>c:\Users\therrera\documents\visual studio 2015\Projects\test\x64\Debug\Project.exe : fatal error LNK1120: 1 externos sin resolver

          If you manually load the m_test.cpp file, in the project, in the GeneratedFiles folder, it runs perfectly.
          It is as if the moc code was not contained in the DLL

          [Added code tags ~kshegunov]

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

            Hi
            It sounds like
            if defined(TEST_LIB)
            define TEST_EXPORT Q_DECL_EXPORT
            is active when you build the app ?

            In sample the key points are
            TEMPLATE = lib <<<
            DEFINES += TEST<<<
            for the LIB, not app.

            So how are you controlling the TEST_LIB when building the lib and the app ?
            for the app, TEST_LIB is not to be defined.

            AEROLASER_THAA 1 Reply Last reply
            2
            • mrjjM mrjj

              Hi
              It sounds like
              if defined(TEST_LIB)
              define TEST_EXPORT Q_DECL_EXPORT
              is active when you build the app ?

              In sample the key points are
              TEMPLATE = lib <<<
              DEFINES += TEST<<<
              for the LIB, not app.

              So how are you controlling the TEST_LIB when building the lib and the app ?
              for the app, TEST_LIB is not to be defined.

              AEROLASER_THAA Offline
              AEROLASER_THAA Offline
              AEROLASER_THA
              wrote on last edited by
              #17

              @mrjj
              Yes, is active

              //DLL
              Preprocessor;
              UNICODE;WIN32;WIN64;QT_DLL;QT_CORE_LIB;QT_GUI_LIB;QT_WIDGETS_LIB;TEST_LIB;%(PreprocessorDefinitions)
              Linker;
              qtmaind.lib;Qt5Cored.lib;Qt5Guid.lib;Qt5Widgetsd.lib;%(AdditionalDependencies)

              //PROJECT
              Preprocessor;
              UNICODE;WIN32;WIN64;QT_DLL;QT_CORE_LIB;QT_GUI_LIB;QT_WIDGETS_LIB;TEST_LIB;%(PreprocessorDefinitions)
              Linker;
              qtmaind.lib;Qt5Cored.lib;Qt5Guid.lib;Qt5Widgetsd.lib;test.lib;%(AdditionalDependencies)

              But it only runs correctly, if in the project manually load the moc_test.cpp

              1 Reply Last reply
              0
              • mrjjM Offline
                mrjjM Offline
                mrjj
                Lifetime Qt Champion
                wrote on last edited by
                #18

                So you are 100% sure that its Q_DECL_IMPORT when building the app and
                Q_DECL_EXPORT when building the LIB/DLL ?
                Sorry I cannot see it from your output.
                Both seems to say TEST_LIB; which is wrong.
                Only
                //DLL
                Preprocessor;
                should have it.

                AEROLASER_THAA 1 Reply Last reply
                0
                • mrjjM mrjj

                  So you are 100% sure that its Q_DECL_IMPORT when building the app and
                  Q_DECL_EXPORT when building the LIB/DLL ?
                  Sorry I cannot see it from your output.
                  Both seems to say TEST_LIB; which is wrong.
                  Only
                  //DLL
                  Preprocessor;
                  should have it.

                  AEROLASER_THAA Offline
                  AEROLASER_THAA Offline
                  AEROLASER_THA
                  wrote on last edited by
                  #19

                  @mrjj

                  TEST_LIB is declared in both DLL and Project

                  If I do not declare in Project, in preprocessor, it gives me error.

                  moc_test.cpp
                  1>..\test\GeneratedFiles\Debug\moc_test.cpp(56): warning C4273: 'Widget::qt_static_metacall': vinculación de DLL incoherente
                  1> c:\users\therrera\documents\visual studio 2015\projects\test\test\generatedfiles\debug../../test.h(10): note: vea la definición anterior de 'qt_static_metacall'
                  1>..\test\GeneratedFiles\Debug\moc_test.cpp(63): warning C4273: 'staticMetaObject': vinculación de DLL incoherente
                  1> c:\users\therrera\documents\visual studio 2015\projects\test\test\generatedfiles\debug../../test.h(10): note: vea la definición anterior de 'public: static QMetaObject const Widget::staticMetaObject'
                  1>..\test\GeneratedFiles\Debug\moc_test.cpp(63): error C2491: 'Widget::staticMetaObject': definición de miembro de datos estático dllimport no permitida
                  1>..\test\GeneratedFiles\Debug\moc_test.cpp(70): warning C4273: 'Widget::metaObject': vinculación de DLL incoherente
                  1> c:\users\therrera\documents\visual studio 2015\projects\test\test\generatedfiles\debug../../test.h(10): note: vea la definición anterior de 'metaObject'
                  1>..\test\GeneratedFiles\Debug\moc_test.cpp(75): warning C4273: 'Widget::qt_metacast': vinculación de DLL incoherente
                  1> c:\users\therrera\documents\visual studio 2015\projects\test\test\generatedfiles\debug../../test.h(10): note: vea la definición anterior de 'qt_metacast'
                  1>..\test\GeneratedFiles\Debug\moc_test.cpp(83): warning C4273: 'Widget::qt_metacall': vinculación de DLL incoherente
                  1> c:\users\therrera\documents\visual studio 2015\projects\test\test\generatedfiles\debug../../test.h(10): note: vea la definición anterior de 'qt_metacall'
                  1> main.cpp

                  mrjjM 1 Reply Last reply
                  0
                  • AEROLASER_THAA AEROLASER_THA

                    @mrjj

                    TEST_LIB is declared in both DLL and Project

                    If I do not declare in Project, in preprocessor, it gives me error.

                    moc_test.cpp
                    1>..\test\GeneratedFiles\Debug\moc_test.cpp(56): warning C4273: 'Widget::qt_static_metacall': vinculación de DLL incoherente
                    1> c:\users\therrera\documents\visual studio 2015\projects\test\test\generatedfiles\debug../../test.h(10): note: vea la definición anterior de 'qt_static_metacall'
                    1>..\test\GeneratedFiles\Debug\moc_test.cpp(63): warning C4273: 'staticMetaObject': vinculación de DLL incoherente
                    1> c:\users\therrera\documents\visual studio 2015\projects\test\test\generatedfiles\debug../../test.h(10): note: vea la definición anterior de 'public: static QMetaObject const Widget::staticMetaObject'
                    1>..\test\GeneratedFiles\Debug\moc_test.cpp(63): error C2491: 'Widget::staticMetaObject': definición de miembro de datos estático dllimport no permitida
                    1>..\test\GeneratedFiles\Debug\moc_test.cpp(70): warning C4273: 'Widget::metaObject': vinculación de DLL incoherente
                    1> c:\users\therrera\documents\visual studio 2015\projects\test\test\generatedfiles\debug../../test.h(10): note: vea la definición anterior de 'metaObject'
                    1>..\test\GeneratedFiles\Debug\moc_test.cpp(75): warning C4273: 'Widget::qt_metacast': vinculación de DLL incoherente
                    1> c:\users\therrera\documents\visual studio 2015\projects\test\test\generatedfiles\debug../../test.h(10): note: vea la definición anterior de 'qt_metacast'
                    1>..\test\GeneratedFiles\Debug\moc_test.cpp(83): warning C4273: 'Widget::qt_metacall': vinculación de DLL incoherente
                    1> c:\users\therrera\documents\visual studio 2015\projects\test\test\generatedfiles\debug../../test.h(10): note: vea la definición anterior de 'qt_metacall'
                    1> main.cpp

                    mrjjM Offline
                    mrjjM Offline
                    mrjj
                    Lifetime Qt Champion
                    wrote on last edited by
                    #20

                    @AEROLASER_THA
                    hmm. ok. im going to try the small test project and see.
                    You added a UI files also ?

                    1 Reply Last reply
                    0
                    • AEROLASER_THAA Offline
                      AEROLASER_THAA Offline
                      AEROLASER_THA
                      wrote on last edited by
                      #21

                      In this example, I am not using ui files

                      AEROLASER_THAA 1 Reply Last reply
                      0
                      • AEROLASER_THAA AEROLASER_THA

                        In this example, I am not using ui files

                        AEROLASER_THAA Offline
                        AEROLASER_THAA Offline
                        AEROLASER_THA
                        wrote on last edited by AEROLASER_THA
                        #22

                        @AEROLASER_THA

                        Dear All;
                        I finally found the problem.
                        I was creating a DLL project, and within this project I created the EXE project.
                        When declaring the path of the inclusion directories of the EXE project, it was not correctly including the address of the path where the lib

                        And indeed my initial confusion was due to the fact of trying to export a template as a class T that is not known.

                        Excuse me

                        .\GeneratedFiles;.;$(QTDIR)\include;.\GeneratedFiles$(ConfigurationName);$(QTDIR)\include\QtCore;$(QTDIR)\include\QtGui;$(QTDIR)\include\QtWidgets;..\test;..\test\GeneratedFiles$(ConfigurationName);C:\Users\therrera\Documents\Visual Studio 2015\Projects\test\x64\Debug;C:\Users\therrera\Documents\Visual Studio 2015\Projects\test\test\x64\Debug;C:\Users\therrera\Documents\Visual Studio 2015\Projects\test\test\GeneratedFiles\Debug;C:\Users\therrera\Documents\Visual Studio 2015\Projects\test\test;%(AdditionalIncludeDirectories)

                        1 Reply Last reply
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