如何修改pyqt5 messagebox以永久显示按钮上的快捷键

from PyQt5.QtWidgets import QMessageBox, QPushButton, QApplication, QVBoxLayout, QWidget, QShortcut
from PyQt5.QtCore import Qt, QEvent
from PyQt5.QtGui import QKeySequence

class CustomMessageBox(QMessageBox):
    def __init__(self, *args, **kwargs):
        super(CustomMessageBox, self).__init__(*args, **kwargs)

    def event(self, event):
        if event.type() == QEvent.KeyPress:
            # 获取按下的键
            key = event.key()
            
            # 遍历对话框上的所有按钮
            for button in self.buttons():
                # 获取按钮上的快捷键
                shortcut = button.shortcut().toString()

                # 判断按下的键是否与按钮上的快捷键相匹配
                if key == QKeySequence(shortcut).standard()[0]:
                    # 模拟按钮被点击
                    button.animateClick()

        # 保留原有事件处理
        return super(CustomMessageBox, self).event(event)

# 创建应用程序和主窗口
app = QApplication([])
window = QWidget()

# 创建自定义消息框
message_box = CustomMessageBox()
message_box.setWindowTitle("Custom MessageBox")
message_box.setText("This is a custom MessageBox.")

# 创建自定义按钮
ok_button = QPushButton("OK")
ok_button.setShortcut(Qt.Key_Enter)  # 设置快捷键为Enter

cancel_button = QPushButton("Cancel")
cancel_button.setShortcut(Qt.Key_Escape)  # 设置快捷键为Esc

# 将按钮添加到消息框中
message_box.addButton(ok_button, QMessageBox.AcceptRole)
message_box.addButton(cancel_button, QMessageBox.RejectRole)

# 创建垂直布局并将消息框添加到主窗口中
layout = QVBoxLayout()
layout.addWidget(message_box)
window.setLayout(layout)

window.show()
app.exec_()