#include <QApplication>
#include <QScreen>
#include <QDebug>int main(int argc, char *argv[])
{     
QApplication a(argc, argv); 
auto const pScreen = a.primaryScreen(); 
MainWindow w;     
w.show();     
qDebug("Screen resolution is %i %i", pScreen->size().width(), pScreen->size().height());       
return a.exec();
}