Qt：将quick的控件图像保存为QImage

QImage itemToImage(QObject *object)
{
    auto item = qobject_cast<QQuickItem*>(object);
    if(!item) { return QImage(); }

    QEventLoop eventLoop;
    QImage buf;
    auto grad = item->grabToImage();

    auto c = QObject::connect(grad.data(), &QQuickItemGrabResult::ready, [&]()
    {
        buf = grad->image();
        eventLoop.exit();
    });
    eventLoop.exec();
    QObject::disconnect(c);

    return buf;
}