打印不适用于QPrinter和QPainter

Question

I want to print some message via my printer, but nothing happens when I compile. What is the problem with my code?

QPrinter printer(QPrinter::HighResolution);
printer.setCreator("Me");
printer.setDocName("Test1");

QPrintDialog *PrintConfiguration = new QPrintDialog(&printer,this);
PrintConfiguration->show();

QPainter *painter = new QPainter(&printer);
painter.drawText(10,10,ui->textEdit->toPlainText());

Answer 1

The code, as presented, won't do anything since you never destruct the painter nor finish the page. You need to destruct the painter: delete painter; . Alternatively, if you print multiple pages, you need to call printer.newPage() every time you're done with a page.

The drawText may very likely draw in a non-printable area of the page. Try:

painter->drawText(printer.pageRect(), ui->textEdit->toPlainText());

Answer 2

Problem is here: PrintConfiguration->show();
show() preparers widget to be show and immediately returns. So result is that you are trying to paint before user managed to do any interaction with UI and you printer object is not set properly. You wanted a blocking method: exec() . Proper code should look like this:

QPrinter printer(QPrinter::HighResolution);
printer.setCreator("Me");
printer.setDocName("Test1");

QPrintDialog printDialog(printer, this);
if (printDialog.exec() == QDialog::Accepted) {
    QPainter painter(&printer);
    painter.drawText(10,10,ui->textEdit->toPlainText());
}