qt-creator/doc/examples/progressbar/main.cpp

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QQuickView>

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);

    QGuiApplication app(argc, argv);

    QQuickView view;
    view.setSource(QUrl("qrc:/qml/ProgressBar.ui.qml"));
    if (!view.errors().isEmpty())
        return -1;
    view.show();

    app.exec();
}