pyqt如何更改任务栏关闭按钮的触发事件

# 重写closeEvent方法，实现dialog窗体关闭时执行一些代码
from PyQt5 import QtCore, QtGui, QtWidgets
import sys

class Dialog(QtWidgets.QMainWindow):

    def get_thread(self, main_thread):
        self.main_thread = main_thread

    def closeEvent(self, event):
        """
        重写closeEvent方法，实现dialog窗体关闭时执行一些代码
        :param event: close()触发的事件
        :return: None
        """
        reply = QtWidgets.QMessageBox.question(self,
                                               ‘本程序‘,
                                               "是否要退出程序？",
                                               QtWidgets.QMessageBox.Yes | QtWidgets.QMessageBox.No,
                                               QtWidgets.QMessageBox.No)
        if reply == QtWidgets.QMessageBox.Yes:
            event.accept()
            sys.exit(0)
        else:
            event.ignore()

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file ‘dialog.ui‘
#
# Created by: PyQt5 UI code generator 5.10.1
#
# WARNING! All changes made in this file will be lost!

from PyQt5 import QtCore, QtGui, QtWidgets
import sys


class Ui_Dialog(object):
    def setupUi(self, Dialog):
        Dialog.setObjectName("Dialog")
        Dialog.resize(640, 480)
        self.pushButton = QtWidgets.QPushButton(Dialog)
        self.pushButton.setGeometry(QtCore.QRect(370, 80, 113, 32))
        self.pushButton.setObjectName("pushButton")
        self.lineEdit = QtWidgets.QLineEdit(Dialog)
        self.lineEdit.setGeometry(QtCore.QRect(140, 80, 113, 21))
        self.lineEdit.setObjectName("lineEdit")
        self.textBrowser = QtWidgets.QTextBrowser(Dialog)
        self.textBrowser.setGeometry(QtCore.QRect(180, 200, 256, 192))
        self.textBrowser.setObjectName("textBrowser")
        self.label = QtWidgets.QLabel(Dialog)
        self.label.setGeometry(QtCore.QRect(30, 80, 111, 16))
        self.label.setObjectName("label")
        self.label_2 = QtWidgets.QLabel(Dialog)
        self.label_2.setGeometry(QtCore.QRect(30, 220, 141, 16))
        self.label_2.setObjectName("label_2")

        self.retranslateUi(Dialog)
        QtCore.QMetaObject.connectSlotsByName(Dialog)

    def retranslateUi(self, Dialog):
        _translate = QtCore.QCoreApplication.translate
        Dialog.setWindowTitle(_translate("Dialog", "Dialog"))
        self.pushButton.setText(_translate("Dialog", "PushButton"))
        self.label.setText(_translate("Dialog", "这是Line Edit ->"))
        self.label_2.setText(_translate("Dialog", "这是Text Browser ->"))


class Dialog(QtWidgets.QMainWindow):
    """对QDialog类重写，实现一些功能"""

    def closeEvent(self, event):
        """
        重写closeEvent方法，实现dialog窗体关闭时执行一些代码
        :param event: close()触发的事件
        :return: None
        """
        reply = QtWidgets.QMessageBox.question(self,
                                               ‘本程序‘,
                                               "是否要退出程序？",
                                               QtWidgets.QMessageBox.Yes | QtWidgets.QMessageBox.No,
                                               QtWidgets.QMessageBox.No)
        if reply == QtWidgets.QMessageBox.Yes:
            event.accept()
        else:
            event.ignore()


def main():
    """
    主函数，用于运行程序
    :return: None
    """
    app = QtWidgets.QApplication(sys.argv)
    dialog = Dialog()  # 注意修改为了自己重写的Dialog类
    ui = Ui_Dialog()
    ui.setupUi(dialog)
    dialog.show()  # 显示了自己重写的Dialog类
    sys.exit(app.exec_())


if __name__ == ‘__main__‘:
    main()