Can not print to paper in Qt - qt

Question

I can not print to paper for some reasone. So I have a functional printer. And I use the folowing code to print a qDialog and a few pictures out:
QPrinter printer;
QPainter painter;
painter.begin(&printer);
double xscale = printer.width() / double(window->width());
double yscale = printer.height() / double(window->height());
double scale = qMin(xscale, yscale);
painter.scale(scale, scale);
QPrintDialog printDialog(&printer, this);
if (printDialog.exec() == QDialog::Accepted) {
bool skip = true;
if(ui->generalInfos->isChecked()) {
//window is a QDialog I want to print out
window->render(&painter);
skip = false;
}
QList<Document *> docs;
if(worker) {
//a list with path to pictures
docs = worker->getDocuments();
}
for(auto document : docs) {
if(ui->Documents->isChecked(document->getID())) {
for(auto scan : document->getScans()) {
if(!skip) {
printer.newPage();
}
else {
skip = false;
}
painter.resetTransform();
const QImage image(scan);
const QPoint imageCoordinates(0,0);
xscale = printer.width() / double(image.width());
yscale = printer.height() / double(image.height());
scale = qMin(xscale, yscale);
painter.scale(scale, scale);
painter.drawImage(imageCoordinates,image);
}
}
}
}
painter.end();
and it doesn't work. Nothing is printed and Qt trows an error:
QWin32PrintEngine::newPage: EndPage failed (The parameter is incorrect.)
QWin32PrintEngine::end: EndPage failed (0x31210cf7) (The parameter is incorrect.)
can someone please help me?

Answer 1

If you simplify your code, you will probably find the solution.
So lets start with selecting the printer, then (afterwards!) start painting to the printer:
QPrinter printer;
QPrintDialog printDialog(&printer, this);
if (printDialog.exec() == QDialog::Accepted)
{
QPainter painter;
painter.begin(&printer);
window->render(&painter);
painter.end();
}
If this works, add more of your old code to the sketch above.
If it doesn't work, something else in your program or your environment (selected printer?) is wrong, so you need to extend your bug hunt beyond what you showed us here.