英文引用网址: https://www3.sra.co.jp/qt/relation/doc/qtwebengine/qtwebengine-webenginewidgets-printme-example.html

做个纪录,以便以后参考:

In the main function, we first instantiate a QWebEngineView and set the URL to our internal HTML page. Next, we create a PrintHandler instance and pass the requested page. For convenience, we also create keyboard shortcuts that can be used to call a print dialog or print preview dialog.

QWebEngineView view;

view.setUrl(QUrl(QStringLiteral("qrc:/index.html")));

view.resize(1024, 750);

view.show();

PrintHandler handler;

handler.setPage(view.page());

auto printPreviewShortCut = new QShortcut(QKeySequence(Qt::CTRL + Qt::Key_P), &view);

auto printShortCut = new QShortcut(QKeySequence(Qt::CTRL + Qt::SHIFT + Qt::Key_P), &view);

QObject::connect(printPreviewShortCut, &QShortcut::activated, &handler, &PrintHandler::printPreview);

QObject::connect(printShortCut, &QShortcut::activated, &handler, &PrintHandler::print);

Print Handler

In the PrintHandler function, we first implement printPreview(), where we instantiate QPrinter together with QPrintPreviewDialog. We need the QPrintPreviewDialog::paintRequested handle to generate a set of preview pages.

void PrintHandler::printPreview()

{

if (!m_page)

return;

if (m_inPrintPreview)

return;

m_inPrintPreview = true;

QPrinter printer;

QPrintPreviewDialog preview(&printer, m_page->view());

connect(&preview, &QPrintPreviewDialog::paintRequested,

this, &PrintHandler::printDocument);

preview.exec();

m_inPrintPreview = false;

}

Now we can implement the PrintHandler::printDocument() slot, which is called in response to the QPrintPreviewDialog::paintRequested signal.

void PrintHandler::printDocument(QPrinter *printer)

{

QEventLoop loop;

bool result;

auto printPreview = [&](bool success) { result = success; loop.quit(); };

m_page->print(printer, std::move(printPreview));

loop.exec();

if (!result) {

QPainter painter;

if (painter.begin(printer)) {

QFont font = painter.font();

font.setPixelSize(20);

painter.setFont(font);

painter.drawText(QPointF(10,25),

QStringLiteral("Could not generate print preview."));

painter.end();

}

}

}

To do actual painting on a printer, we call the QWebEnginePage::print() function. Because this call blocks the main event loop, we need to create a local one. We begin the local event loop by calling QEventLoop::exec(). When the local event loop terminates, we check for result and report any errors that occurred.

The last function we implement, PrintHandler::print(), is trivial, because it simply opens QPrintDialog and calls the previously implemented PrintHandler::printDocument().

void PrintHandler::print()

{

QPrinter printer(QPrinter::HighResolution);

QPrintDialog dialog(&printer, m_page->view());

if (dialog.exec() != QDialog::Accepted)

return;

printDocument(&printer);

}