Call to QPainter::begin() crashes when trying to print using Microsoft to PDF.

[Antonio L.]

This application generates a test pdf file using QPrinter and QPainter. The call to QPainter::begin() opens a dialog used to enter the PDF file name and location:

#include <iostream>
#include <QApplication>
#include <QPrinterInfo>
#include <QPainter>
 
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
 
    foreach(QPrinterInfo printerInfo, QPrinterInfo::availablePrinters()) {
        if (printerInfo.state() == QPrinter::PrinterState::Error)
            continue;
 
        // Look for the virtual printer device that generates a pdf.
        if (printerInfo.printerName() == "Microsoft Print to PDF")
        {
            QPrinter * qPrinter = new QPrinter(printerInfo, QPrinter::HighResolution);
            QPainter * qPainter = new QPainter();
 
            // This statement pops up a file selection dialog.
            // When it is cancelled, the application crashes ...
            qPainter->begin(qPrinter);
 
            // ... and this statement is never reached.
            std::cout << "Starting printing on the pdf file." << std::endl;
 
            // We print some text in the PDF file.
            qPainter->drawText(100, 100, "Lorem ipsum dolor sit amet, consectetur adipiscing elit.");
            qPrinter->newPage();
            qPainter->drawText(100, 100, "Mauris ut urna eget dui eleifend placerat.");
            qPrinter->newPage();
 
            // Close the printer and clean-up.
            qPainter->end();
            delete qPrinter;
            delete qPainter;
        }
    }
 
    return 0;
}

#include <iostream>
#include <QApplication>
#include <QPrinterInfo>
#include <QPainter>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    foreach(QPrinterInfo printerInfo, QPrinterInfo::availablePrinters()) {
        if (printerInfo.state() == QPrinter::PrinterState::Error)
            continue;

        // Look for the virtual printer device that generates a pdf.
        if (printerInfo.printerName() == "Microsoft Print to PDF")
        {
            QPrinter * qPrinter = new QPrinter(printerInfo, QPrinter::HighResolution);
            QPainter * qPainter = new QPainter();

            // This statement pops up a file selection dialog.
            // When it is cancelled, the application crashes ...
            qPainter->begin(qPrinter);

            // ... and this statement is never reached.
            std::cout << "Starting printing on the pdf file." << std::endl;

            // We print some text in the PDF file.
            qPainter->drawText(100, 100, "Lorem ipsum dolor sit amet, consectetur adipiscing elit.");
            qPrinter->newPage();
            qPainter->drawText(100, 100, "Mauris ut urna eget dui eleifend placerat.");
            qPrinter->newPage();

            // Close the printer and clean-up.
            qPainter->end();
            delete qPrinter;
            delete qPainter;
        }
    }

    return 0;
}

To copy to clipboard, switch view to plain text mode 

It works correctly when a PDF file name is introduced in the dialog. However, by clicking on the Cancel button the application crashes during the call to QPainter::begin().

Is there a way to prevent this crash? Is the previous code correct, or is there something missing?

Thanks in advance and best regards.

[anda_skoa]

You could explicitly ask for a file name using QFileDialog and then configure the QPrinter object with it.
Maybe even use a QPrintDialog

Cheers,
_