当上下文菜单在QGraphicsPixmapItem中打开时，如何删除此QGraphicsLineItem？

#include <QGraphicsPixmapItem>
#include <QGraphicsLineItem>
#include <QGraphicsScene>
#include <QMenu>

class MyGraphicsPixmapItem : public QGraphicsPixmapItem
{
public:
    MyGraphicsPixmapItem(QGraphicsItem* parent = nullptr)
        : QGraphicsPixmapItem(parent)
    {
        // 创建关联的QGraphicsLineItem
        lineItem = new QGraphicsLineItem(this);
        // 设置lineItem的位置和样式
        lineItem->setLine(0, 0, 100, 100);
        lineItem->setPen(QPen(Qt::red, 2));

        // 创建上下文菜单
        contextMenu = new QMenu();
        // 添加删除操作
        QAction* deleteAction = contextMenu->addAction("删除");
        // 将删除操作与删除信号关联
        connect(deleteAction, &QAction::triggered, this, &MyGraphicsPixmapItem::deleteLineItem);

        // 启用上下文菜单
        setFlag(QGraphicsItem::ItemIsSelectable, true);
        setFlag(QGraphicsItem::ItemIsFocusable, true);
        setAcceptHoverEvents(true);
        setContextMenuPolicy(Qt::CustomContextMenu);
    }

protected:
    void contextMenuEvent(QGraphicsSceneContextMenuEvent* event) override
    {
        contextMenu->exec(event->screenPos());
    }

private slots:
    void deleteLineItem()
    {
        // 删除QGraphicsLineItem
        scene()->removeItem(lineItem);
        delete lineItem;
    }

private:
    QGraphicsLineItem* lineItem;
    QMenu* contextMenu;
};