connect() problem

[harmodrew]

I've changed the code and now it works!

QPushButton *NewButton= new QPushButton(this);
NewButton->setText("Button");
 
actionsObj *ao= new actionsObj;
connect(NewButton, SIGNAL(clicked()),ao,  SLOT(ButtonClicked()));
NewButton->setGeometry(50, 40, 300, 200);
NewButton->show();
//ui->setupUi(this);

QPushButton *NewButton= new QPushButton(this);
NewButton->setText("Button");

actionsObj *ao= new actionsObj;
connect(NewButton, SIGNAL(clicked()),ao,  SLOT(ButtonClicked()));
NewButton->setGeometry(50, 40, 300, 200);
NewButton->show();
//ui->setupUi(this);

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the only problem now is that if I uncomment the last row the button isn't clickable anymore. What could be the problem?

[harmodrew]

ok, I've done it!
simply, the ui->setupUi(this); row is to be written before the other rows, not in the bottom
thanks you all

[harmodrew]

here I am again for the same problem...
mainwindow.cpp:

#include "mainwindow.h"
#include "ui_mainwindow.h"
 #include <QObject>
 
class act :public QObject
{
    Q_OBJECT
 
};
 
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
 
    act *ao= new act;
}
 
MainWindow::~MainWindow()
{
    delete ui;
}

#include "mainwindow.h"
#include "ui_mainwindow.h"
 #include <QObject>

class act :public QObject
{
    Q_OBJECT

};

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    act *ao= new act;
}

MainWindow::~MainWindow()
{
    delete ui;
}

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this little code returns me the same error:

collect2: Id returned 1 exit status

what it refers to??
in addition if I comment the Q_OBJECT line it compiles without errors!

[Lykurg]

put your class act in a single file or make sure moc runing right for your class. Simpliest is every class a single file!

[harmodrew]

thanks for the reply, it helped! but, why are we obliged to write the class in an another file to make it work? what does it change?

[squidge]

Its to do with the meta object compiler. You can have classes in the same file as your .cpp if you want, but if they include the Q_OBJECT macro, then you need to run MOC, so ideally those classes should be in .h files instead.

[harmodrew]

oh, it's clear now! thank again!