[TOC] ## 概述 - 是Qt中用于處理各種數據類型的通用數據容器類 - `QVariant`支持許多不同的Qt和C++數據類型，包括整數、浮點數、字符串、日期、時間、顏色、點、尺寸、矩形等 支持的類型 <details> <summary>支持的類型</summary> ``` enum Type { Invalid = QMetaType::UnknownType, Bool = QMetaType::Bool, Int = QMetaType::Int, UInt = QMetaType::UInt, LongLong = QMetaType::LongLong, ULongLong = QMetaType::ULongLong, Double = QMetaType::Double, Char = QMetaType::QChar, Map = QMetaType::QVariantMap, List = QMetaType::QVariantList, String = QMetaType::QString, StringList = QMetaType::QStringList, ByteArray = QMetaType::QByteArray, BitArray = QMetaType::QBitArray, Date = QMetaType::QDate, Time = QMetaType::QTime, DateTime = QMetaType::QDateTime, Url = QMetaType::QUrl, Locale = QMetaType::QLocale, Rect = QMetaType::QRect, RectF = QMetaType::QRectF, Size = QMetaType::QSize, SizeF = QMetaType::QSizeF, Line = QMetaType::QLine, LineF = QMetaType::QLineF, Point = QMetaType::QPoint, PointF = QMetaType::QPointF, RegExp = QMetaType::QRegExp, RegularExpression = QMetaType::QRegularExpression, Hash = QMetaType::QVariantHash, Uuid = QMetaType::QUuid, ModelIndex = QMetaType::QModelIndex, PersistentModelIndex = QMetaType::QPersistentModelIndex, LastCoreType = QMetaType::LastCoreType, Font = QMetaType::QFont, Pixmap = QMetaType::QPixmap, Brush = QMetaType::QBrush, Color = QMetaType::QColor, Palette = QMetaType::QPalette, Image = QMetaType::QImage, Polygon = QMetaType::QPolygon, Region = QMetaType::QRegion, Bitmap = QMetaType::QBitmap, Cursor = QMetaType::QCursor, KeySequence = QMetaType::QKeySequence, Pen = QMetaType::QPen, TextLength = QMetaType::QTextLength, TextFormat = QMetaType::QTextFormat, Matrix = QMetaType::QMatrix, Transform = QMetaType::QTransform, Matrix4x4 = QMetaType::QMatrix4x4, Vector2D = QMetaType::QVector2D, Vector3D = QMetaType::QVector3D, Vector4D = QMetaType::QVector4D, Quaternion = QMetaType::QQuaternion, PolygonF = QMetaType::QPolygonF, Icon = QMetaType::QIcon, LastGuiType = QMetaType::LastGuiType, SizePolicy = QMetaType::QSizePolicy, UserType = QMetaType::User, LastType = 0xffffffff // need this so that gcc >= 3.4 allocates 32 bits for Type }; ``` </details> ## 示例 ``` QVariant::Type type = var.type(); qDebug() << type; // QVariant::int int retrievedIntValue = var.value<int>(); qDebug() << retrievedIntValue; //123 var.setValue(QString("hello world")); QVariant::Type type1 = var.type(); qDebug() << type1; // QVariant::QString QString retrievedIntValue1 = var.value<QString>(); qDebug() << retrievedIntValue1; //hello world ```