如何在PyQt5中为对话框添加最小化和最大化图标？

from PyQt5.QtWidgets import QApplication, QDialog, QSystemTrayIcon, QStyle, QMenu, QAction
from PyQt5.QtGui import QIcon

class MyDialog(QDialog):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        # 设置对话框标题和大小
        self.setWindowTitle("My Dialog")
        self.resize(300, 200)

def initUI(self):
    # 设置对话框标题和大小
    self.setWindowTitle("My Dialog")
    self.resize(300, 200)

    # 创建系统托盘图标
    self.tray_icon = QSystemTrayIcon(self)
    self.tray_icon.setIcon(self.style().standardIcon(QStyle.SP_TitleBarMaxButton))

    # 创建菜单
    menu = QMenu(self)
    restore_action = QAction("Restore", self)
    quit_action = QAction("Quit", self)
    menu.addAction(restore_action)
    menu.addAction(quit_action)

    # 将菜单添加到系统托盘图标
    self.tray_icon.setContextMenu(menu)
    self.tray_icon.show()

def initUI(self):
    # 设置对话框标题和大小
    self.setWindowTitle("My Dialog")
    self.resize(300, 200)

    # 创建系统托盘图标
    self.tray_icon = QSystemTrayIcon(self)
    self.tray_icon.setIcon(self.style().standardIcon(QStyle.SP_TitleBarMaxButton))

    # 创建菜单
    menu = QMenu(self)
    restore_action = QAction("Restore", self)
    quit_action = QAction("Quit", self)
    menu.addAction(restore_action)
    menu.addAction(quit_action)

    # 将菜单添加到系统托盘图标
    self.tray_icon.setContextMenu(menu)
    self.tray_icon.show()

    # 最小化和最大化功能的槽函数
    restore_action.triggered.connect(self.showNormal)
    quit_action.triggered.connect(QApplication.instance().quit)

if __name__ == '__main__':
    app = QApplication(sys.argv)
    dialog = MyDialog()
    dialog.show()
    sys.exit(app.exec_())