C++ Qt signal and slot not firing

Question

I am having difficulty in my Qt program with connecting button signals to my slots. My code is:

Main.cpp

#include 
#include         


        

Answer 1

Add Q_OBJECT to your class, like this:

class MainWidget : public QWidget
{
    Q_OBJECT

You also have to run moc to generate some helper code. qmake does that automatically for your, but if you compile this yourself, you need to run moc.

Answer 2

Edited:

Compiled your code and all the slots were correctly called. It was just the Q_OBJECT macro that was missing.

Answer 3

When I started with Qt, I had this problem a lot. As I see it your slots are defined wrong. If you look at the signature for the signal (Qt Clicked Signal Docs), you will see that the argument list is (bool clicked = false).

The way Qt's signal & slots connect work at run time, is that it will only connect the signal and slot if they have the exact same signatures. If they don't match exactly, no connection.

so in MainWidget.h

 public slots:
        void bAdvice_clicked(bool);

In MainWidget.cpp

  connect(bAdvice, SIGNAL(clicked(bool)), this, SLOT(bAdvice_clicked(bool)));

Things will start working for you.