connecting signal from thread to slot in a cpp file

I am trying to connect a signal from a thread to a slot in a cpp file.
I am able to successfully connect it to Main Window slot,but not through a cpp file.
Here is what I am doing
//abc.h

Code:

---

#ifndef ABC_H
#define ABC_H
#include <QObject>
 
class abc : public QObject
{    
    Q_OBJECT
public:
    explicit abc(QObject *parent = 0);
public slots:
    void AbcInvokeSlot();
};
 
#endif // ABC_H

---

//abc.cpp

Code:

---

#include "abc.h"
abc::abc(QObject *parent) :
    QObject(parent)
{
}
void abc :: AbcInvokeSlot()
{    
//some code
}

---

//main.cpp

Code:

---

QApplication app(argc, argv);
    MainWindow win;
    abc a;
    win.show();
    SThread sthread;    
    QObject::connect( & sthread, SIGNAL( SInSignal() ),& win, SLOT( SOutSlot() ) ); //correctly working
    QObject::connect( & sthread, SIGNAL( SInSignal() ),& a, SLOT( AbcInvokeSlot() ) );    //not working
         sthread.start();         
    return app.exec();

---

I am getting the error :

Quote:

---

undefined reference to 'vtable for abc'

---

I tried changing

Code:

---

abc a;

---

to

Code:

---

abc a=new abc;

---

then I am getting this error:

Quote:

---

no matching function for call to 'QObject::connect(SThread*, const char*, abc**, const char*)'

---

May I know what I am doing wrong and what is the correct procedure??

Rerun qmake and rebuild your program.

As ChrisW67 said, run qmake again.

Your code is fine, the error is caused by adding Q_OBJECT to a header after the header has been added to the project file and the related qmake run.

Classes with Q_OBJECT need to be processed by MOC and these processing instructions are created by qmake.
If you add Q_OBJECT after a header file has been "seen" by qmake, then certain bit will be missing at link time.

Rerunning qmake (and completing the hew build) solves that.

Cheers,
_

Thank you for the solution and explanation.It exactly solved my problem!!