DLL export problem

[hrcariaga]

hi to all!

i've created a simple program with export(i'm not sure if my export code is right) and compile it as .dll..

then i'm trying to access the .dll using delphi.. but the problem is i can't acces the function in my .dll.. please help..

heres my code:

//in .h

class q_decl_export dialogimpl : public qdialog, public ui.html#Dialog
{
Q_OBJECT
public:
    DialogImpl;
#endif" class="bbcodeurl">#ifndef DIALOGIMPL_H
#define DIALOGIMPL_H
#include <QDialog>
#include "ui_dialog.h"
 
class Q_DECL_EXPORT DialogImpl : public QDialog, public Ui::Dialog
{
Q_OBJECT
public:
    DialogImpl( QWidget * parent = 0, Qt::WFlags f = 0 );
    void ShowMessage();
private slots:
};
Q_DECL_EXPORT void ShowMessage();
#endif
//in .cpp
 
#include 
 
//
q_decl_export dialogimpl.html#DialogImpl;
}" class="bbcodeurl">#include "dialogimpl.h"
#include <QMessageBox>
 
//
Q_DECL_EXPORT DialogImpl::DialogImpl( QWidget * parent, Qt::WFlags f) 
    : QDialog(parent, f)
{
    setupUi(this);
    ShowMessage();
}
 
Q_DECL_EXPORT void DialogImpl::ShowMessage()
{
    QMessageBox::information(this, tr("DLL"),"DLL exported!");
}

class q_decl_export dialogimpl : public qdialog, public ui.html#Dialog
{
Q_OBJECT
public:
    DialogImpl;
#endif" class="bbcodeurl">#ifndef DIALOGIMPL_H
#define DIALOGIMPL_H
#include <QDialog>
#include "ui_dialog.h"

class Q_DECL_EXPORT DialogImpl : public QDialog, public Ui::Dialog
{
Q_OBJECT
public:
    DialogImpl( QWidget * parent = 0, Qt::WFlags f = 0 );
    void ShowMessage();
private slots:
};
Q_DECL_EXPORT void ShowMessage();
#endif
//in .cpp

#include 

//
q_decl_export dialogimpl.html#DialogImpl;
}" class="bbcodeurl">#include "dialogimpl.h"
#include <QMessageBox>

//
Q_DECL_EXPORT DialogImpl::DialogImpl( QWidget * parent, Qt::WFlags f) 
    : QDialog(parent, f)
{
    setupUi(this);
    ShowMessage();
}

Q_DECL_EXPORT void DialogImpl::ShowMessage()
{
    QMessageBox::information(this, tr("DLL"),"DLL exported!");
}

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[jpn]

Unfortunately it's not correct. You can't hardcode Q_DECL_EXPORT like that. You must use Q_DECL_EXPORT when building the library and Q_DECL_IMPORT when using the library. For more details, see this thread: Q_DECL_EXPORT and Q_DECL_IMPORT.

[hrcariaga]

Unfortunately it's not correct. You can't hardcode Q_DECL_EXPORT like that. You must use Q_DECL_EXPORT when building the library and Q_DECL_IMPORT when using the library. For more details, see this thread: Q_DECL_EXPORT and Q_DECL_IMPORT.

i've changed my first code to this:

in .h

#ifndef DIALOGIMPL_H
#define DIALOGIMPL_H
#include <QDialog>
#include "ui_dialog.h"
 
#ifndef _DLL_BUILD_
    #if (defined(QT_DLL) || defined(QT_SHARED)) && !defined(QT_PLUGIN)
        #define EXPORT Q_DECL_EXPORT
    #else
        #define EXPORT
    #endif
#else
        #define EXPORT Q_DECL_IMPORT
#endif 
 
 
class EXPORT DialogImpl : public QDialog, public Ui::Dialog
{
Q_OBJECT
public:
	DialogImpl( QWidget * parent = 0, Qt::WFlags f = 0 );
	void ShowMessage();
private slots:
};
 
EXPORT void ShowMessage();
#endif

#ifndef DIALOGIMPL_H
#define DIALOGIMPL_H
#include <QDialog>
#include "ui_dialog.h"

#ifndef _DLL_BUILD_
    #if (defined(QT_DLL) || defined(QT_SHARED)) && !defined(QT_PLUGIN)
        #define EXPORT Q_DECL_EXPORT
    #else
        #define EXPORT
    #endif
#else
        #define EXPORT Q_DECL_IMPORT
#endif 


class EXPORT DialogImpl : public QDialog, public Ui::Dialog
{
Q_OBJECT
public:
	DialogImpl( QWidget * parent = 0, Qt::WFlags f = 0 );
	void ShowMessage();
private slots:
};

EXPORT void ShowMessage();
#endif

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in .cpp

#include "dialogimpl.h"
#include <QMessageBox>
 
EXPORT DialogImpl::DialogImpl( QWidget * parent, Qt::WFlags f) 
	: QDialog(parent, f)
{
	setupUi(this);
	ShowMessage();
}
 
EXPORT void DialogImpl::ShowMessage()
{
	QMessageBox::information(this, tr("DLL"),"DLL exported!");
}

#include "dialogimpl.h"
#include <QMessageBox>

EXPORT DialogImpl::DialogImpl( QWidget * parent, Qt::WFlags f) 
	: QDialog(parent, f)
{
	setupUi(this);
	ShowMessage();
}

EXPORT void DialogImpl::ShowMessage()
{
	QMessageBox::information(this, tr("DLL"),"DLL exported!");
}

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i have build the program without error but still the .dll can't be access by delphi..

hmm, is there any suggestion on how i can solve my problem?

thanks..

[ChristianEhrlicher]

Why do you think you can access C++ code from Delphi? A Qt-Window will never run without a proper QApplication...

[hrcariaga]

I think any program compiled into a .dll can be access/imported by any programming language provided that it is properly exported..

my problem is, I can't find the right code to export my dll..

is there any suggestion on how I can make this?

thanks..

[ChristianEhrlicher]

Did you read my post?

You can't access a QWidget from Delphi (or whatever) because you need a QMainApplication. Also you can't access a C++ class from Delphi at all (imho).