How to Qt screenshot

qt_screenshot.cpp

#include <QPixmap>
#include <QDir>
#include <QFileDialog>
#include <QString>
#include <QScreen>

QPixmap originalPixmap;

originalPixmap = QPixmap(); // clear image for low memory situations
                            // on embedded devices.
//! [5]
QScreen *screen = QGuiApplication::primaryScreen();
if (screen)
    originalPixmap = screen->grabWindow(0);

QString format = "png";
QString initialPath = QDir::currentPath() + QObject::tr("/untitled.") + format;

//    QString fileName = QFileDialog::getSaveFileName(0,QObject::tr("Save As"),
//                            initialPath,
//                            QObject::tr("%1 Files (*.%2);;All Files (*)")
//                            .arg(format.toUpper())
//                            .arg(format));

QString fileName = "C:\\path\\to\\file\\testscreenshot.png";
if (!fileName.isEmpty())
 originalPixmap.save(fileName, format.toLatin1().constData());