如何在Qt中正确实现"最小化托盘"功能？

#include <QApplication>
#include <QMainWindow>
#include <QSystemTrayIcon>
#include <QMenu>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    // 创建主窗口
    QMainWindow *mainWindow = new QMainWindow;
    mainWindow->setWindowTitle("主窗口");

    // 创建托盘图标
    QSystemTrayIcon *trayIcon = new QSystemTrayIcon(mainWindow);
    trayIcon->setIcon(QIcon(":/icon.png"));

    // 创建托盘菜单
    QMenu *trayMenu = new QMenu(mainWindow);
    trayMenu->addAction("最小化", mainWindow, SLOT(showMinimized()));
    trayMenu->addAction("还原", mainWindow, SLOT(showNormal()));
    trayMenu->addSeparator();
    trayMenu->addAction("退出", qApp, SLOT(quit()));

    // 将托盘菜单添加到托盘图标
    trayIcon->setContextMenu(trayMenu);

    // 显示主窗口
    mainWindow->show();

    return app.exec();
}