2

专家您好！！我希望你今天过得愉快。我是 GUI 编程的新手，特别是 PyQt5。我正在练习简单的 GUI 发票应用程序。在这个应用程序中，我成功地生成了 Invoice By QTextDocument。现在我想添加打印对话框和打印预览选项。我在代码中遇到问题。这是在说

AttributeError：“InvoiceForm”对象没有属性“printpreviewDialog”

因为我是新人，所以我在那里有点困惑。你能修复代码吗？这对我学习有很大帮助。非常感谢。代码如下： -

import sys
from PyQt5.QtCore import pyqtSignal, QSize, QSizeF, QDate
from PyQt5.QtGui import QTextDocument, QTextCursor, QFont
from PyQt5.QtPrintSupport import QPrinter, QPrintPreviewDialog
from PyQt5.QtWidgets import QWidget, QFormLayout, QLineEdit, QPlainTextEdit, QSpinBox, QDateEdit, QTableWidget, \
    QHeaderView, QPushButton, QHBoxLayout, QTextEdit, QApplication, QMainWindow

font= QFont('Arial',16)

class InvoiceForm(QWidget):
    submitted = pyqtSignal(dict)
    def __init__(self):
        super().__init__()
        self.setLayout(QFormLayout())
        self.inputs = dict()
        self.inputs['Customer Name'] = QLineEdit()
        self.inputs['Customer Address'] = QPlainTextEdit()
        self.inputs['Invoice Date'] = QDateEdit(date=QDate.currentDate(), calendarPopup=True)
        self.inputs['Days until Due'] = QSpinBox()
        for label, widget in self.inputs.items():
            self.layout().addRow(label, widget)

        self.line_items = QTableWidget(rowCount=10, columnCount=3)
        self.line_items.setHorizontalHeaderLabels(['Job', 'Rate', 'Hours'])
        self.line_items.horizontalHeader().setSectionResizeMode(QHeaderView.Stretch)
        self.layout().addRow(self.line_items)
        for row in range(self.line_items.rowCount()):
            for col in range(self.line_items.columnCount()):
                if col > 0:
                    w = QSpinBox()
                    self.line_items.setCellWidget(row, col, w)

        submit = QPushButton('Create Invoice', clicked=self.on_submit)
        print = QPushButton('Print Invoice', clicked=self.printpreviewDialog)
        self.layout().addRow(submit,print)

    def on_submit(self):
        data = {'c_name': self.inputs['Customer Name'].text(),
                'c_addr': self.inputs['Customer Address'].toPlainText(),
                'i_date': self.inputs['Invoice Date'].date().toString(),
                'i_due': self.inputs['Invoice Date'].date().addDays(self.inputs['Days until Due'].value()).toString(),
                'i_terms': '{} days'.format(self.inputs['Days until Due'].value()),
                'line_items': list()}

        for row in range(self.line_items.rowCount()):
            if not self.line_items.item(row, 0):
                continue
            job = self.line_items.item(row, 0).text()
            rate = self.line_items.cellWidget(row, 1).value()
            hours = self.line_items.cellWidget(row, 2).value()
            total = rate * hours
            row_data = [job, rate, hours, total]
            if any(row_data):
                data['line_items'].append(row_data)

        data['total_due'] = sum(x[3] for x in data['line_items'])
        self.submitted.emit(data)
        # remove everything else in this function below this point

class InvoiceView(QTextEdit):
    dpi = 72
    doc_width = 8.5 * dpi
    doc_height = 6 * dpi

    def __init__(self):
        super().__init__(readOnly=True)
        self.setFixedSize(QSize(self.doc_width, self.doc_height))

    def build_invoice(self, data):
        document = QTextDocument()
        self.setDocument(document)
        document.setPageSize(QSizeF(self.doc_width, self.doc_height))
        document.setDefaultFont(font)
        cursor = QTextCursor(document)
        cursor.insertText(f"Customer Name: {data['c_name']}\n")
        cursor.insertText(f"Customer Address: {data['c_addr']}\n")
        cursor.insertText(f"Date: {data['i_date']}\n")
        cursor.insertText(f"Total Due: {data['total_due']}\n")

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        central = QWidget()
        self.setCentralWidget(central)
        layout = QHBoxLayout(central)

        self.invoiceForm = InvoiceForm()
        layout.addWidget(self.invoiceForm)

        self.invoiceView = InvoiceView()
        layout.addWidget(self.invoiceView)
        # hide the widget right now...
        self.invoiceView.setVisible(False)

        self.invoiceForm.submitted.connect(self.showPreview)

    def showPreview(self, data):
        self.invoiceView.setVisible(True)
        self.invoiceView.build_invoice(data)

    def printpreviewDialog(self):
        printer = QPrinter(QPrinter.HighResolution)
        previewDialog = QPrintPreviewDialog(printer, self)
        previewDialog.paintRequested.connect(self.printPreview)
        previewDialog.exec_()

    def printPreview(self, printer):
        self.invoiceView.build_invoice.print_(printer)

def main():
    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    app.exec_()

if __name__ == '__main__':
    main()
4

2 回答 2

1

主要问题是它self.printpreviewDialog是 的成员MainWindow，而不是 的成员InvoiceForm，因此您应该连接clicked来自主窗口的信号。

另请注意，您尝试使用self.invoiceView.build_invoice.print_()，但这不起作用，因为您没有调用 build_invoice，即使您这样做了，该函数也不会返回任何内容。

您应该self.invoiceView.document()改用，但您必须确保之前已构建数据。

class InvoiceForm(QWidget):
    submitted = pyqtSignal(dict)
    def __init__(self):
        # ...
        submit = QPushButton('Create Invoice', clicked=self.on_submit)
        # make the button a member of the instance instead of a local variable, 
        # so that we can connect from the main window instance
        self.printButton = QPushButton('Print Invoice')
        self.layout().addRow(submit, self.printButton)

# ...

class MainWindow(QMainWindow):
    def __init__(self):
        # ...
        self.invoiceForm.printButton.clicked.connect(self.printpreviewDialog)
    # ...

    def printPreview(self, printer):
        self.invoiceView.document().print_(printer)

注意：永远，永远不要对变量名使用内置函数和语句，例如print.

于 2020-09-18T15:14:40.580 回答
0

试试看：

import sys
from PyQt5.QtCore import pyqtSignal, QSize, QSizeF, QDate
from PyQt5.QtGui import QTextDocument, QTextCursor, QFont
from PyQt5.QtPrintSupport import QPrinter, QPrintPreviewDialog
from PyQt5.QtWidgets import (QWidget, QFormLayout, QLineEdit, QPlainTextEdit, 
    QSpinBox, QDateEdit, QTableWidget, QHeaderView, QPushButton, QHBoxLayout, 
    QTextEdit, QApplication, QMainWindow)


font = QFont('Arial',16)


class InvoiceForm(QWidget):
    submitted = pyqtSignal(dict)
    
    def __init__(self, parent=None):                                        # + parent=None
        super().__init__(parent)                                            # + parent
        self.setLayout(QFormLayout())
        self.inputs = dict()
        self.inputs['Customer Name'] = QLineEdit()
        self.inputs['Customer Address'] = QPlainTextEdit()
        self.inputs['Invoice Date'] = QDateEdit(date=QDate.currentDate(), calendarPopup=True)
        self.inputs['Days until Due'] = QSpinBox()
        for label, widget in self.inputs.items():
            self.layout().addRow(label, widget)

        self.line_items = QTableWidget(rowCount=10, columnCount=3)
        self.line_items.setHorizontalHeaderLabels(['Job', 'Rate', 'Hours'])
        self.line_items.horizontalHeader().setSectionResizeMode(QHeaderView.Stretch)
        self.layout().addRow(self.line_items)
        for row in range(self.line_items.rowCount()):
            for col in range(self.line_items.columnCount()):
                if col > 0:
                    w = QSpinBox()
                    self.line_items.setCellWidget(row, col, w)

        submit = QPushButton('Create Invoice', clicked=self.on_submit)
        
# +     vvvvvv                                        vvvvvvvvvvvvv 
        _print = QPushButton('Print Invoice', clicked=self.window().printpreviewDialog)  # + _print, + self.window()
        self.layout().addRow(submit, _print)                                             # + _print

    def on_submit(self):
        data = {'c_name': self.inputs['Customer Name'].text(),
                'c_addr': self.inputs['Customer Address'].toPlainText(),
                'i_date': self.inputs['Invoice Date'].date().toString(),
                'i_due': self.inputs['Invoice Date'].date().addDays(self.inputs['Days until Due'].value()).toString(),
                'i_terms': '{} days'.format(self.inputs['Days until Due'].value()),
                'line_items': list()}

        for row in range(self.line_items.rowCount()):
            if not self.line_items.item(row, 0):
                continue
            job = self.line_items.item(row, 0).text()
            rate = self.line_items.cellWidget(row, 1).value()
            hours = self.line_items.cellWidget(row, 2).value()
            total = rate * hours
            row_data = [job, rate, hours, total]
            if any(row_data):
                data['line_items'].append(row_data)

        data['total_due'] = sum(x[3] for x in data['line_items'])
        self.submitted.emit(data)
        # remove everything else in this function below this point
# +
        return data                                                            # +++
        

class InvoiceView(QTextEdit):
    dpi = 72
    doc_width = 8.5 * dpi
    doc_height = 6 * dpi

    def __init__(self):
        super().__init__(readOnly=True)
        self.setFixedSize(QSize(self.doc_width, self.doc_height))

    def build_invoice(self, data):
        document = QTextDocument()
        self.setDocument(document)
        document.setPageSize(QSizeF(self.doc_width, self.doc_height))
        document.setDefaultFont(font)
        cursor = QTextCursor(document)
        cursor.insertText(f"Customer Name: {data['c_name']}\n")
        cursor.insertText(f"Customer Address: {data['c_addr']}\n")
        cursor.insertText(f"Date: {data['i_date']}\n")
        cursor.insertText(f"Total Due: {data['total_due']}\n")
# +        
        return document                                                         # +++
        

class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        central = QWidget()
        self.setCentralWidget(central)
        layout = QHBoxLayout(central)
# +                                    vvvv
        self.invoiceForm = InvoiceForm(self)                                    # + self
        
        layout.addWidget(self.invoiceForm)
        self.invoiceView = InvoiceView()
        layout.addWidget(self.invoiceView)
        # hide the widget right now...
        self.invoiceView.setVisible(False)
        self.invoiceForm.submitted.connect(self.showPreview)

    def showPreview(self, data):
        self.invoiceView.setVisible(True)
        self.invoiceView.build_invoice(data)

# +++ vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
    def printpreviewDialog(self):
        previewDialog = QPrintPreviewDialog()
        previewDialog.paintRequested.connect(self.printPreview)  
        previewDialog.exec_()

    def printPreview(self, printer):
#        self.invoiceView.build_invoice.print_(printer)        
        data = self.invoiceForm.on_submit()
        document = self.invoiceView.build_invoice(data)
        document.print_(printer)
# +++ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


def main():
    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    app.exec_()

if __name__ == '__main__':
    main()

在此处输入图像描述

于 2020-09-18T16:05:40.310 回答