获取内容：

from PyQt5.QtWidgets import QApplication, QMainWindow, QVBoxLayout, QPushButton, QPlainTextEdit
import sysclass MainWindow(QMainWindow):def __init__(self):super().__init__()self.setGeometry(100, 100, 300, 200)layout = QVBoxLayout()text_edit = QPlainTextEdit(self)layout.addWidget(text_edit)button = QPushButton("Get Content", self)button.clicked.connect(lambda: print(text_edit.toPlainText()))layout.addWidget(button)widget = QWidget()widget.setLayout(layout)self.setCentralWidget(widget)if __name__ == "__main__":app = QApplication(sys.argv)window = MainWindow()window.show()sys.exit(app.exec())

追加内容：

from PyQt5.QtWidgets import QApplication, QMainWindow, QVBoxLayout, QPushButton, QPlainTextEdit
import sysclass MainWindow(QMainWindow):def __init__(self):super().__init__()self.setWindowTitle("QPlainTextEdit 追加")layout = QVBoxLayout()text_edit = QPlainTextEdit()button = QPushButton("点击追加文本")layout.addWidget(text_edit)layout.addWidget(button)central_widget = QWidget()central_widget.setLayout(layout)self.setCentralWidget(central_widget)# 连接按钮点击事件到自定义的槽函数button.clicked.connect(lambda: self.append_text(text_edit))def append_text(self, text_edit):current_cursor = text_edit.textCursor()current_cursor.movePosition(current_cursor.End)current_cursor.insertText("\n这是新的文本行")text_edit.setTextCursor(current_cursor)if __name__ == "__main__":app = QApplication(sys.argv)main_window = MainWindow()main_window.show()sys.exit(app.exec())

设置只读：

from PyQt5.QtWidgets import QApplication, QMainWindow, QVBoxLayout, QPlainTextEdit
import sysapp = QApplication(sys.argv)
window = QMainWindow()
layout = QVBoxLayout()
text_edit = QPlainTextEdit("这是一段只读的文本")
text_edit.setReadOnly(True) # 设置为只读模式
layout.addWidget(text_edit)
central_widget = QWidget()
central_widget.setLayout(layout)
window.setCentralWidget(central_widget)
window.show()
sys.exit(app.exec())