我如何在PyQt5中创建QWebEngineView的打印预览？

Question

我正在尝试创建QWebEngineView的打印预览，但无法正常工作。

这是我的代码：

...
self.view = QWebEngineView()
...

def handle_preview(self):
    dialog = QPrintPreviewDialog()
    dialog.paintRequested.connect(self.view.print_)
    dialog.exec_()

代码给我这个错误：

[AttributeError：'QWebEngineView'对象没有属性'print _']

当我使用QTextEdit时，代码可以完美工作。但这不是我想要的。我想使用QWebEngineView。

Answer 1

基于官方示例：WebEngine Widgets PrintMe Example，您可以使用以下代码来实现预览。

import sys

from PyQt5.QtCore import pyqtSlot, QEventLoop, QObject, QPointF, QUrl
from PyQt5.QtGui import QPainter
from PyQt5.QtWidgets import QApplication, QDialog, QPushButton, QVBoxLayout, QWidget
from PyQt5.QtPrintSupport import QPrintDialog, QPrinter, QPrintPreviewDialog
from PyQt5.QtWebEngineWidgets import QWebEnginePage, QWebEngineView


class PrintHandler(QObject):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.m_page = None
        self.m_inPrintPreview = False

    @property
    def page(self):
        return self.m_page

    @page.setter
    def page(self, page):
        if isinstance(page, QWebEnginePage):
            self.m_page = page
            self.page.printRequested.connect(self.printPreview)
        else:
            raise TypeError("page must be a QWebEnginePage")

    @pyqtSlot()
    def print(self):
        printer = QPrinter(QPrinter.HighResolution)
        dialog = QPrintDialog(printer, self.page.view())
        if dialog.exec_() != QDialog.Accepted:
            return
        self.printDocument(printer)

    @pyqtSlot()
    def printPreview(self):
        if self.page is None:
            return
        if self.m_inPrintPreview:
            return
        self.m_inPrintPreview = True
        printer = QPrinter()
        preview = QPrintPreviewDialog(printer, self.page.view())
        preview.paintRequested.connect(self.printDocument)
        preview.exec_()
        self.m_inPrintPreview = False

    @pyqtSlot(QPrinter)
    def printDocument(self, printer):
        result = False
        loop = QEventLoop()

        def printPreview(sucess):
            nonlocal result
            result = sucess
            loop.quit()

        self.page.print(printer, printPreview)
        loop.exec_()
        if not result:
            painter = QPainter()
            if painter.begin(printer):
                font = painter.font()
                font.setPixelSize(20)
                painter.setFont(font)
                painter.drawText(QPointF(10, 25), "Could not generate print preview.")
                painter.end()


class Widget(QWidget):
    def __init__(self, parent=None):
        super().__init__(parent)
        button = QPushButton("Print me")
        self.view = QWebEngineView()
        self.view.load(QUrl("https://stackoverflow.com/questions/59438021"))

        lay = QVBoxLayout(self)
        lay.addWidget(button)
        lay.addWidget(self.view)
        self.resize(640, 480)

        handler = PrintHandler(self)
        handler.page = self.view.page()
        button.clicked.connect(handler.printPreview)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    w = Widget()
    w.show()
    sys.exit(app.exec_())