【PyQt5-Qt Designer】读取txt文件在打印

 from PyQt5.QtGui import QFont,QTextDocument,QTextCursor
 from PyQt5.QtWidgets import QApplication, QMainWindow, QLabel, QSizePolicy, QAction,QDialog
 from PyQt5.QtPrintSupport import QPrinter, QPrintDialog,QPrintPreviewDialog
 import sys
 
 ################################################
 #######打印文本---海子的诗
 ################################################
 the_text = '''
 从明天起，做一个幸福的人
 喂马、劈柴，周游世界
 从明天起，关心粮食和蔬菜
 我有一所房子，面朝大海，春暖花开
 从明天起，和每一个亲人通信
 告诉他们我的幸福
 那幸福的闪电告诉我的
 我将告诉每一个人
 给每一条河每一座山取一个温暖的名字
 陌生人，我也为你祝福
 愿你有一个灿烂的前程
 愿你有情人终成眷属
 愿你在尘世获得幸福
 我只愿面朝大海，春暖花开
 '''
 
 class MainWindow(QMainWindow):
     def __init__(self, parent=None):
         super(MainWindow, self).__init__(parent)
         self.setWindowTitle(self.tr("打印功能"))
 
         # 创建文本框
         self.label = QLabel()
         self.label.setFont(QFont("宋体",12,QFont.Bold))
         self.label.setText(the_text)
         self.setCentralWidget(self.label)
 
         # 创建菜单栏
         self.createMenus()
 
     def createMenus(self):
         # 创建动作一
         self.printAction1 = QAction(self.tr("打印无预留"), self)
         self.printAction1.triggered.connect(self.on_printAction1_triggered)
 
         # 创建动作二
         self.printAction2 = QAction(self.tr("打印有预留"), self)
         self.printAction2.triggered.connect(self.on_printAction2_triggered)
 
         # 创建动作三
         self.printAction3 = QAction(self.tr("直接打印"), self)
         self.printAction3.triggered.connect(self.on_printAction3_triggered)
 
         # 创建动作四
         self.printAction4 = QAction(self.tr("打印到PDF"), self)
         self.printAction4.triggered.connect(self.on_printAction4_triggered)
 
         # 创建菜单，添加动作
         self.printMenu = self.menuBar().addMenu(self.tr("打印"))
         self.printMenu.addAction(self.printAction1)
         self.printMenu.addAction(self.printAction2)
         self.printMenu.addAction(self.printAction3)
         self.printMenu.addAction(self.printAction4)
 
     # 动作一：打印，无预览
     def on_printAction1_triggered(self):
         printer = QPrinter()
         printDialog = QPrintDialog(printer, self)
         if printDialog.exec_() == QDialog.Accepted:
             self.handlePaintRequest(printer)
 
     # 动作二：打印，有预览
     def on_printAction2_triggered(self):
         dialog = QPrintPreviewDialog()
         dialog.paintRequested.connect(self.handlePaintRequest)
         dialog.exec_()
 
     # 动作三：直接打印
     def on_printAction3_triggered(self):
         printer = QPrinter()
         self.handlePaintRequest(printer)
 
     # 动作四：打印到pdf
     def on_printAction4_triggered(self):
         printer = QPrinter()
         printer.setOutputFormat(QPrinter.PdfFormat)
         printer.setOutputFileName("D:/pdf打印测试.pdf")
         self.handlePaintRequest(printer)
 
     ## 打印函数
     def handlePaintRequest(self, printer):
         document = QTextDocument()
         cursor = QTextCursor(document)
         cursor.insertText(self.label.text())
         document.print(printer)
 
 if __name__ == "__main__":
     app = QApplication(sys.argv)
     main = MainWindow()
     main.show()
     sys.exit(app.exec_())