#include
int main(int argv, char **args)
{
QApplication app(argv, args);
QRadialGradient radialGrad(QPointF(100, 100), 100);
radialGrad.setColorAt(0, Qt::red);
radialGrad.setColorAt(0.5, Qt::blue);
radialGrad.setColorAt(1, Qt::green);
QBrush brush(radialGrad);
QWidget widget;
QPalette palette;
palette.setBrush(widget.backgroundRole(), brush);
widget.setPalette(palette);
widget.show();
return app.exec();
}