Connecting button to an arbitrary function

Question

Myself trying to write a program in Qt connecting a function to a button in Qt5.

 #include <QApplication>
 #include <QtGui>
 #include <QPushButton>
 static void insert()
 {
     qDebug() << “pressed”;
 }

 int main(int argc,char *argv[])
 {
     QApplication app(argc,argv);
     QPushButton *button=new QPushButton(“button”);
     button->setGeometry(50,100,150,80);
     QObject::connect(button,&QPushButton::clicked,insert());
     button->show();
  }

But I am getting errors like main.cc:23:39: error: within this context main.cc:23:55: error: invalid use of void expression make: * [main.o] Error 1

Please help…

Answer 1

In Qt 5, you need to use the new qt signal and slots system. The connection will look like :

QObject::connect(button,&QPushButton::clicked,insert); <-- no parentheses.

It has already been stated, but you need to call app.exec(); to start the event loop processing. Otherwise the connection will never be triggered.

Furthermore, if you are on release mode then you may not see the output of qDebug()