Slot in inherited class is not working...

[phamtv]

I have an inherited class from a base class that is derived from QObject. Can someone tell me why my inherited class slot is not being invoked..

@
class cls_A : public QObject
{
Q_OBJECT

private:
explicit cls_A(QObject *parent = 0);

// etc......

}

class cls_B : public cls_A
{
private:
cls_B()
{
// instantiate Serial Device Enumerator and get available serial ports
m_sde = new SerialDeviceEnumerator(this);
connect(m_sde, SIGNAL(hasChanged(QStringList)), this, SLOT(GetDevices(QStringList)));
m_sde->setEnabled(true);
}

private slots:
void GetDevices(const QStringList &list)
{
// do something....
}
//......
}
@

I run the application but GetDevices is not being invoked... Does cls_B have to have the Q_OBJECT declaration?

[goetz]

Yes, every class that inherits from QObject - regardless wheter direct or in an inheritance path - must include the Q_OBJECT macro in the private section of the class definition.

[phamtv]

when I do place the Q_OBJECT macro, I get an error indicating ¨error: undefined reference to `vtable for cls_B¨... what does this error imply?

[goetz]

Did you re-run qmake? It must pick up the new header and include some additional build steps for a QObject class with the Q_OBJECT macro in it. You also must add the header file to the HEADERS variable in the .pro file.

[anselmolsm]

Also, if you declare and implement classes in the same file filename, you'll need a

@
#include "filename.moc"
@

[Polto]

hi i think i works for me but
try to put the implement of the class constructor and other function in a cpp file not within the class
and put Q_OBJECT for the two classes