使用 PyQt5/6 将 QTableWidget 导出为 pdf

Question

我制作了一个带有数据和导出到 pdf 按钮的 QTableWidget，我制作了一个功能，它进行下载并将 pdf 文件放入选定的文件夹中，但该文件无法打开。

这是我的代码

import test

class recordsWindow(QMainWindow):
    def __init__(self, record_list=None):
        super().__init__()
         ....  
    

        # present records chart
        record_list = test.show_records(self)

        self.tableWidget.setColumnCount(5)
        self.tableWidget.setHorizontalHeaderLabels(["Blod Type", "Donation Date", "First Name", "Last Name", "ID"])
        self.tableWidget.setColumnWidth(0, 125)
        self.tableWidget.setColumnWidth(1, 125)
        self.tableWidget.setColumnWidth(2, 125)
        self.tableWidget.setColumnWidth(3, 125)
        self.tableWidget.setColumnWidth(4,125)

        self.tableWidget.setRowCount(len(record_list))

        i=0
        for record in record_list:
            self.tableWidget.setItem(i, 0, QTableWidgetItem((record[0])))
            self.tableWidget.setItem(i, 1, QTableWidgetItem((record[1])))
            self.tableWidget.setItem(i, 2, QTableWidgetItem((record[2])))
            self.tableWidget.setItem(i, 3, QTableWidgetItem((record[3])))
            self.tableWidget.setItem(i, 4, QTableWidgetItem((record[4])))
            i+=1

        # activate export
        self.pushButton.clicked.connect(self.exportPDF)


    def exportPDF(self):
        filename, _ = QFileDialog.getSaveFileName(self, "Export PDF", "", "PDF files (*.pdf)")
        if filename:
            printer = QPrinter(QPrinter.PrinterMode.HighResolution)
            printer.setOutputFormat(QPrinter.OutputFormat.PdfFormat)
            printer.setOutputFileName(filename)
            printer.setPageSize(QPageSize(QPageSize.A4))

            try:
                painter = QPainter()
                painter.begin(printer)

                # render the table into the painter object
                self.tableWidget.render(painter)

                painter.end()
                print("PDF generated successfully")
            except Exception as e:
                print("PDF generation failed: ", e)

实际上并没有生成 vlid 文件。也没有收到任何异常或错误。