QVariant

最新推荐文章于 2025-06-12 16:23:19 发布

翻译最新推荐文章于 2025-06-12 16:23:19 发布 · 置顶 · 3.4k 阅读

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#string #qt #c

本文深入探讨了QVariant类，作为C++联合数据类型的实现，它可以存储多种Qt数据类型。文章介绍了其基本声明和使用方法，以及如何通过多种转换函数来灵活地处理不同数据类型之间的转换。

QVariant 类，类似于C++的联合数据类型，他能保存很多Qt数据。

声明：

v= QVarient ("hello world");

QString string=v.toString();

先声明，然后调用相关的函数就行了。

它好多可供转化的函数：

QVariant ()
	QVariant ( const QLocale & l )
	QVariant ( const QRegExp & regExp )
	QVariant ( const QEasingCurve & val )
	QVariant ( Qt::GlobalColor color )
	QVariant ( Type type )
	QVariant ( int typeOrUserType, const void * copy )
	QVariant ( const QVariant & p )
	QVariant ( QDataStream & s )
	QVariant ( int val )
	QVariant ( uint val )
	QVariant ( qlonglong val )
	QVariant ( qulonglong val )
	QVariant ( bool val )
	QVariant ( double val )
	QVariant ( float val )
	QVariant ( const char * val )
	QVariant ( const QByteArray & val )
	QVariant ( const QBitArray & val )
	QVariant ( const QString & val )
	QVariant ( const QLatin1String & val )
	QVariant ( const QStringList & val )
	QVariant ( const QChar & c )
	QVariant ( const QDate & val )
	QVariant ( const QTime & val )
	QVariant ( const QDateTime & val )
	QVariant ( const QList<QVariant> & val )
	QVariant ( const QMap<QString, QVariant> & val )
	QVariant ( const QHash<QString, QVariant> & val )
	QVariant ( const QSize & val )
	QVariant ( const QSizeF & val )
	QVariant ( const QPoint & val )
	QVariant ( const QPointF & val )
	QVariant ( const QLine & val )
	QVariant ( const QLineF & val )
	QVariant ( const QRect & val )
	QVariant ( const QRectF & val )
	QVariant ( const QUrl & val )
	~QVariant ()
bool	canConvert ( Type t ) const
bool	canConvert () const
void	clear ()
bool	convert ( Type t )
bool	isNull () const
bool	isValid () const
void	setValue ( const T & value )
void	swap ( QVariant & other )
QBitArray	toBitArray () const
bool	toBool () const
QByteArray	toByteArray () const
QChar	toChar () const
QDate	toDate () const
QDateTime	toDateTime () const
double	toDouble ( bool * ok = 0 ) const
QEasingCurve	toEasingCurve () const
float	toFloat ( bool * ok = 0 ) const
QHash<QString, QVariant>	toHash () const
int	toInt ( bool * ok = 0 ) const
QLine	toLine () const
QLineF	toLineF () const
QList<QVariant>	toList () const
QLocale	toLocale () const
qlonglong	toLongLong ( bool * ok = 0 ) const
QMap<QString, QVariant>	toMap () const
QPoint	toPoint () const
QPointF	toPointF () const
qreal	toReal ( bool * ok = 0 ) const
QRect	toRect () const
QRectF	toRectF () const
QRegExp	toRegExp () const
QSize	toSize () const
QSizeF	toSizeF () const
QString	toString () const
QStringList	toStringList () const
QTime	toTime () const
uint	toUInt ( bool * ok = 0 ) const
qulonglong	toULongLong ( bool * ok = 0 ) const
QUrl	toUrl () const
Type	type () const
const char *	typeName () const
int	userType () const
T	value () const
bool	operator!= ( const QVariant & v ) const
QVariant &	operator= ( const QVariant & variant )
bool	operator== ( const QVariant & v ) const