上述代码提示error: reference to type 'const QCursor' could not bind to an rvalue of type 'Qt::CursorShape'

抱歉，我的代码有误，应该是 `QCursor(Qt::ClosedHandCursor)` 和 `QCursor(Qt::ArrowCursor)`。 `QCursor` 不能直接绑定到 `Qt::CursorShape` 枚举类型。下面是修正过的代码：

class MyRectItem : public QGraphicsItem
{
public:
    MyRectItem(QGraphicsItem *parent = nullptr)
        : QGraphicsItem(parent)
    {
        setFlags(ItemIsMovable | ItemSendsGeometryChanges);
    }

    QRectF boundingRect() const override
    {
        return QRectF(-50, -50, 100, 100);
    }

    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) override
    {
        painter->setBrush(Qt::red);
        painter->drawRect(boundingRect());
    }

protected:
    void mousePressEvent(QGraphicsSceneMouseEvent *event) override
    {
        if (event->button() == Qt::LeftButton)
        {
            m_lastPos = event->pos();
            setCursor(QCursor(Qt::ClosedHandCursor));
        }
    }

    void mouseMoveEvent(QGraphicsSceneMouseEvent *event) override
    {
        if (event->buttons() & Qt::LeftButton)
        {
            QPointF delta = event->pos() - m_lastPos;
            m_lastPos = event->pos();

            QGraphicsRectItem *guideRect = new QGraphicsRectItem(boundingRect(), this);
            guideRect->setPen(QPen(Qt::DashLine));
            guideRect->setBrush(Qt::NoBrush);
            guideRect->setPos(pos() + delta);

            setCursor(QCursor(Qt::ClosedHandCursor));
        }
    }

    void mouseReleaseEvent(QGraphicsSceneMouseEvent *event) override
    {
        if (event->button() == Qt::LeftButton)
        {
            QGraphicsItem *item = scene()->itemAt(event->scenePos(), QTransform());
            if (item && item->parentItem() == this)
            {
                setPos(item->pos());
            }

            QList<QGraphicsItem *> itemList = scene()->items(event->scenePos());
            for (QGraphicsItem *item : itemList)
            {
                if (item->parentItem() == this)
                {
                    delete item;
                }
            }

            setCursor(QCursor(Qt::ArrowCursor));
        }
    }

private:
    QPointF m_lastPos;
};

感谢您指出我的错误。