pyqt如何显示和打印本地pdf文件

在PyQt中，可以使用`PyQt5.QtPrintSupport`模块来展示和打印PDF文件，通常会结合`QPrinter`和`QPrintDialog`类来完成。以下是基本的步骤：

1. 首先，确保已安装了`PyQt5`以及支持PDF阅读的第三方库，如`qrcode`（用于生成二维码，以便预览）、`PDFdocument`等。

import sys
from PyQt5.QtCore import Qt
from PyQt5.QtGui import QImageReader, QPixmap, QPrinter
from PyQt5.QtWidgets import QApplication, QMainWindow, QAction, QLabel, QMessageBox

2. 加载PDF文件并转换成QImage:

def load_pdf(pdf_path):
    reader = QImageReader(pdf_path)
    if not reader.supportedImageFormats():
        QMessageBox.warning(None, "Error", f"Unsupported PDF format for {pdf_path}")
        return None
    image = reader.read()
    if not image:
        QMessageBox.warning(None, "Error", f"Failed to read {pdf_path}")
        return None
    return image

image = load_pdf('path_to_your_pdf.pdf')

3. 创建QLabel来显示PDF图片，并用QPrintDialog预览和打印：

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        
        self.pdf_label = QLabel(self)
        self.setCentralWidget(self.pdf_label)

        action = QAction("Print", self)
        action.triggered.connect(self.print_pdf)
        self.addAction(action)

    def print_pdf(self):
        printer = QPrinter()
        dialog = QPrintDialog(printer, self)
        if dialog.exec_() == QDialog.Accepted:
            painter = QPainter(printer)
            pixmap = QPixmap.fromImage(image)
            painter.drawPixmap(0, 0, pixmap)
            painter.end()

# 实例化并运行主窗口
app = QApplication(sys.argv)
window = MainWindow()
window.show()
sys.exit(app.exec_())

4.