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，但我无法让它工作。

这是我的代码：

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

代码给了我这个错误：

属性错误："QWebEngineView"对象没有属性"print_">

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

Answer 1

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

from PyQt5.QtCore import (QCoreApplication, QEventLoop, QObject, QPointF, Qt,
QUrl, pyqtSlot)
from PyQt5.QtGui import QKeySequence, QPainter
from PyQt5.QtPrintSupport import QPrintDialog, QPrinter, QPrintPreviewDialog
from PyQt5.QtWebEngineWidgets import QWebEnginePage, QWebEngineView
from PyQt5.QtWidgets import QApplication, QDialog, QLabel, QProgressBar, QProgressDialog, QShortcut

class PrintHandler(QObject):
def __init__(self, parent = None):
super().__init__(parent)
self.m_page = None
self.m_inPrintPreview = False
def setPage(self, page):
assert not self.m_page
self.m_page = page
self.m_page.printRequested.connect(self.printPreview)
@pyqtSlot()
def print(self):
printer = QPrinter(QPrinter.HighResolution)
dialog = QPrintDialog(printer, self.m_page.view())
if dialog.exec_() != QDialog.Accepted:
return
self.printDocument(printer)
@pyqtSlot()
def printPreview(self):
if not self.m_page:
return
if self.m_inPrintPreview:
return
self.m_inPrintPreview = True
printer = QPrinter()
preview = QPrintPreviewDialog(printer, self.m_page.view())
preview.paintRequested.connect(self.printDocument)
preview.exec()
self.m_inPrintPreview = False
@pyqtSlot(QPrinter)
def printDocument(self, printer):
loop = QEventLoop()
result = False
def printPreview(success):
nonlocal result
result = success
loop.quit()
progressbar = QProgressDialog(self.m_page.view())
progressbar.findChild(QProgressBar).setTextVisible(False)
progressbar.setLabelText("Wait please...")
progressbar.setRange(0, 0)
progressbar.show()
progressbar.canceled.connect(loop.quit)
self.m_page.print(printer, printPreview)
loop.exec_()
progressbar.close()
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()

def main():
import sys
QCoreApplication.setAttribute(Qt.AA_EnableHighDpiScaling)
app = QApplication(sys.argv)
app.setApplicationName("Previewer")
view = QWebEngineView()
view.setUrl(QUrl("https://stackoverflow.com/questions/59438021"))
view.resize(1024, 750)
view.show()
handler = PrintHandler()
handler.setPage(view.page())
printPreviewShortCut = QShortcut(QKeySequence(Qt.CTRL + Qt.Key_P), view)
printShortCut = QShortcut(QKeySequence(Qt.CTRL + Qt.SHIFT + Qt.Key_P), view)
printPreviewShortCut.activated.connect(handler.printPreview)
printShortCut.activated.connect(handler.print)
sys.exit(app.exec_())

if __name__ == "__main__":
main()

注意：对于 PySide2，您只需将pyqtSlot更改为Slot。