Create circle using QPainter

marlenet15

I found the following code which does exactly what I want it to do. However, The QPixmap is making it have a white square background instead of having the same color background as the window which is like gray. Is there anyway to display circle without the white background?

#include <QtGui>

int main(int argc, char* argv[])
{
 QApplication app(argc, argv);
 QPixmap pm(100,100);
 pm.fill();

 QPainter p(&pm);
 p.setRenderHint(QPainter::Antialiasing, true);
 QPen pen(Qt::blue, 2);
 p.setPen(pen);
 QBrush brush(Qt::green);
 p.setBrush(brush);
 p.drawEllipse(10, 10, 80, 80);
 QLabel l;
 l.setPixmap(pm);
 l.show();
 return app.exec();
}

Eddy

the docs tell us white is the default background color

void QPixmap::fill(const QColor & color = Qt::white)
Fills the pixmap with the given color.

you could use :
pm.fill(QColor(255, 0, 0, 0));
to get a transparant fill

marlenet15

Thank you!!!