Question

如何将Qt的QVariant转换为boost :: any？

Answer 1

我不认为有一个简单的方法，我会做以下：

boost::any qvariant_to_any(const QVariant& v) {
    switch(v.userType()) {
        case QVariant::Bool:
            return boost::any(v.value<bool>());
            //or: return boost::any(v.toBool());
        case QVariant::Int:
            return boost::any(v.value<int>());
            //or: return boost::any(v.toInt());
        case QVariant::UInt:
            return boost::any(v.value<unsigned>());
        // ...
        // all your types which store in a QVariant in your use case
        case QVariant::Invalid:
        default:
            throw std::bad_cast(); //or return default constructed boost::any
    }
}

如果Boost.Variant会做这个工作而不是Boost.Any，在德国杂志上有一篇很好的文章关于将QVariant转换为Boost.Variant，反之亦然，如果这会让你感兴趣，请查看源代码：
德国文章：http://www.heise.de/developer/artikel/Konvertierungen-992950.html 来源：ftp://ftp.heise.de/pub/ix/developer/elfenbein.zip

Answer 2

我希望通过详细阐述merlins很好的答案来节省一些人打字。

boost::any QVariantToAny(const QVariant& v) {
    switch(v.userType()) {
        case QVariant::BitArray:
            return boost::any(v.value<QBitArray>());
        case QVariant::Bitmap:
            return boost::any(v.value<QBitmap>());
        case QVariant::Bool:
            return boost::any(v.value<bool>());
        case QVariant::Brush:
            return boost::any(v.value<QBrush>());
        case QVariant::ByteArray:
            return boost::any(v.value<QByteArray>());
        case QVariant::Char:
            return boost::any(v.value<QChar>());
        case QVariant::Color:
            return boost::any(v.value<QColor>());
        case QVariant::Cursor:
            return boost::any(v.value<QCursor>());
        case QVariant::Date:
            return boost::any(v.value<QDate>());
        case QVariant::DateTime:
            return boost::any(v.value<QDateTime>());
        case QVariant::Double:
            return boost::any(v.value<double>());
        case QVariant::EasingCurve:
            return boost::any(v.value<QEasingCurve>());
        case QVariant::Font:
            return boost::any(v.value<QFont>());
        case QVariant::Hash:
            return boost::any(v.value<QVariantHash>());
        case QVariant::Icon:
            return boost::any(v.value<QIcon>());
        case QVariant::Image:
            return boost::any(v.value<QImage>());
        case QVariant::Int:
            return boost::any(v.value<int>());
        case QVariant::KeySequence:
            return boost::any(v.value<QKeySequence>());
        case QVariant::Line:
            return boost::any(v.value<QLine>());
        case QVariant::LineF:
            return boost::any(v.value<QLineF>());
        case QVariant::List:
            return boost::any(v.value<QVariantList>());
        case QVariant::Locale:
            return boost::any(v.value<QLocale>());
        case QVariant::LongLong:
            return boost::any(v.value<qlonglong>());
        case QVariant::Map:
            return boost::any(v.value<QVariantMap>());
        case QVariant::Matrix:
            return boost::any(v.value<QMatrix>());
        case QVariant::Transform:
            return boost::any(v.value<QTransform>());
        case QVariant::Matrix4x4:
            return boost::any(v.value<QMatrix4x4>());
        case QVariant::Palette:
            return boost::any(v.value<QPalette>());
        case QVariant::Pen:
            return boost::any(v.value<QPen>());
        case QVariant::Pixmap:
            return boost::any(v.value<QPixmap>());
        case QVariant::Point:
            return boost::any(v.value<QPoint>());
        case QVariant::PointArray:
            return boost::any(v.value<QPointArray>());
        case QVariant::PointF:
            return boost::any(v.value<QPointF>());
        case QVariant::Polygon:
            return boost::any(v.value<QPolygon>());
        case QVariant::Quaternion:
            return boost::any(v.value<QQuaternion>());
        case QVariant::Rect:
            return boost::any(v.value<QRect>());
        case QVariant::RectF:
            return boost::any(v.value<QRectF>());
        case QVariant::RegExp:
            return boost::any(v.value<QRegExp>());
        case QVariant::Region:
            return boost::any(v.value<QRegion>());
        case QVariant::Size:
            return boost::any(v.value<QSize>());
        case QVariant::SizeF:
            return boost::any(v.value<QSizeF>());
        case QVariant::SizePolicy:
            return boost::any(v.value<QSizePolicy>());
        case QVariant::String:
            return boost::any(v.value<QString>());
        case QVariant::StringList:
            return boost::any(v.value<QStringList>());
        case QVariant::TextFormat:
            return boost::any(v.value<QTextFormat>());
        case QVariant::TextLength:
            return boost::any(v.value<QTextLength>());
        case QVariant::Time:
            return boost::any(v.value<QTime>());
        case QVariant::UInt:
            return boost::any(v.value<unsigned>());
        case QVariant::ULongLong:
            return boost::any(v.value<qulonglong>());
        case QVariant::Url:
            return boost::any(v.value<QUrl>());
        case QVariant::Vector2D:
            return boost::any(v.value<QVector2D>());
        case QVariant::Vector3D:
            return boost::any(v.value<QVector3D>());
        case QVariant::Vector4D:
            return boost::any(v.value<QVector4D>());
        case QVariant::UserType: 
        case QVariant::Invalid:
        default:
            throw std::bad_cast(); //or return default constructed boost::any
    }
}

如何将Qt的QVariant转换为boost :: any？

2 个答案: