error LNK2001: unresolved external symbol "public: static struct QMetaObject const BUtils

JoeCFD

I have a small qt class BUtils with export definition. It is defined in one module BMesh(dll) and can be compiled in the module BMesh without issue in VIsual Studio. Then I use BUtils in another module(dll) TBase. I added qt libraries, BMesh.lib and include paths in the
properties of module TBase. I started to recompile TBase and got the linking error:

.obj : error LNK2001: unresolved external symbol "public: static struct QMetaObject const BUtils::staticMetaObject

I have another static variable defined in BUtils and got the following error:
.obj : error LNK2001: unresolved external symbol "public: static bool BUtils::m_bStop"
It seems only related to static definition. I have another nonstatic funcion and there is no error message to complains about
that one. What is wrong? Thanks for your help

SGaist

Hi,

Can you show how you exported your class ?

JoeCFD

============================Global.h==========================

#ifndef GLOBAL_H
#define GLOBAL_H

#  ifndef Global_EXPORT
#  define Global_EXPORT __declspec( dllexport )
#endif

===========================BUtils.h===========================

#ifndef BUtils_H
#define BUtils_H

#include "Global.h"
#include <QtCore/QObject>

class Global_EXPORT BUtils : public QObject
{
    Q_OBJECT
    
public:
    static bool m_bStop;
    
    void sendPercent( double percent );

signals:
    void emitPercent( double );
};

#endif

===========================BUtils.cpp==================================

#include "BUtils.h"

bool BUtils::m_bStop = false;

void BUtils::sendPercent( double percent )
{
    emit emitPercent( percent );
}

[edit: Added missing coding tags SGaist]

SGaist

Ok, you only did half the work regarding symbol handling. There's exporting and importing symbols on Windows.

You can find a nice example on how to do that in the Creating Shared Libraries chapter of Qt's documentation

JoeCFD

Got it. Thanks a lot

Joe

SGaist

You're welcome !

Since you have it working now, please mark the thread as solved using the "Topic Tool" button so that other forum users may know a solution has been found :)

JoeCFD

Vielen Dank!