qvariant.3qt

linux下GUI编程工具qt的在线连接帮助手册

.PP
Returns a reference to the stored font.
.PP
See also toFont().
.SH "QIconSet & QVariant::asIconSet ()"
Tries to convert the variant to hold a QIconSet value. If that is not possible the variant is set to an empty iconset.
.PP
Returns a reference to the stored iconset.
.PP
See also toIconSet().
.SH "QImage & QVariant::asImage ()"
Tries to convert the variant to hold an image value. If that is not possible the variant is set to a null image.
.PP
Returns a reference to the stored image.
.PP
See also toImage().
.SH "int & QVariant::asInt ()"
Returns the variant's value as int reference.
.SH "QKeySequence & QVariant::asKeySequence ()"
Tries to convert the variant to hold a QKeySequence value. If that is not possible then the variant is set to an empty key sequence.
.PP
Returns a reference to the stored key sequence.
.PP
See also toKeySequence().
.SH "QValueList<QVariant> & QVariant::asList ()"
Returns the variant's value as variant list reference.
.SH "QMap<QString, QVariant> & QVariant::asMap ()"
Returns the variant's value as variant map reference.
.SH "QPalette & QVariant::asPalette ()"
Tries to convert the variant to hold a QPalette value. If that is not possible the variant is set to a palette with black colors only.
.PP
Returns a reference to the stored palette.
.PP
See also toString().
.SH "QPixmap & QVariant::asPixmap ()"
Tries to convert the variant to hold a pixmap value. If that is not possible the variant is set to a null pixmap.
.PP
Returns a reference to the stored pixmap.
.PP
See also toPixmap().
.SH "QPoint & QVariant::asPoint ()"
Tries to convert the variant to hold a point value. If that is not possible the variant is set to a null point.
.PP
Returns a reference to the stored point.
.PP
See also toPoint().
.SH "QPointArray & QVariant::asPointArray ()"
Tries to convert the variant to hold a QPointArray value. If that is not possible the variant is set to an empty point array.
.PP
Returns a reference to the stored point array.
.PP
See also toPointArray().
.SH "QRect & QVariant::asRect ()"
Tries to convert the variant to hold a rectangle value. If that is not possible the variant is set to an empty rectangle.
.PP
Returns a reference to the stored rectangle.
.PP
See also toRect().
.SH "QRegion & QVariant::asRegion ()"
Tries to convert the variant to hold a QRegion value. If that is not possible the variant is set to a null region.
.PP
Returns a reference to the stored region.
.PP
See also toRegion().
.SH "QSize & QVariant::asSize ()"
Tries to convert the variant to hold a QSize value. If that is not possible the variant is set to an invalid size.
.PP
Returns a reference to the stored size.
.PP
See also toSize() and QSize::isValid().
.SH "QSizePolicy & QVariant::asSizePolicy ()"
Tries to convert the variant to hold a QSizePolicy value. If that fails, the variant is set to an arbitrary size policy.
.SH "QString & QVariant::asString ()"
Tries to convert the variant to hold a string value. If that is not possible the variant is set to an empty string.
.PP
Returns a reference to the stored string.
.PP
See also toString().
.SH "QStringList & QVariant::asStringList ()"
Tries to convert the variant to hold a QStringList value. If that is not possible the variant is set to an empty string list.
.PP
Returns a reference to the stored string list.
.PP
See also toStringList().
.SH "QTime & QVariant::asTime ()"
Tries to convert the variant to hold a QTime value. If that is not possible then the variant is set to an invalid time.
.PP
Returns a reference to the stored time.
.PP
See also toTime().
.SH "uint & QVariant::asUInt ()"
Returns the variant's value as unsigned int reference.
.SH "bool QVariant::canCast ( Type t ) const"
Returns TRUE if the variant's type can be cast to the requested type, \fIt\fR. Such casting is done automatically when calling the toInt(), toBool(), ... or asInt(), asBool(), ... methods.
.PP
The following casts are done automatically:
.TP
Bool => Double, Int, UInt
.TP
CString => String
.TP
Date => String
.TP
DateTime => String, Date, Time
.TP
Double => String, Int, Bool, UInt
.TP
Int => String, Double, Bool, UInt
.TP
List => StringList (if the list contains strings or something that can be cast to a string)
.TP
String => CString, Int, Uint, Double, Date, Time, DateTime
.TP
StringList => List
.TP
Time => String
.TP
UInt => String, Double, Bool, Int
.SH "bool QVariant::cast ( Type t )"
Casts the variant to the requested type. If the cast cannot be done, the variant is set to the default value of the requested type (e.g. an empty string if the requested type \fIt\fR is QVariant::String, an empty point array if the requested type \fIt\fR is QVariant::PointArray, etc). Returns TRUE if the current type of the variant was successfully casted; otherwise returns FALSE.
.PP
See also canCast().
.SH "void QVariant::clear ()"
Convert this variant to type Invalid and free up any resources used.
.SH "bool QVariant::isValid () const"
Returns TRUE if the storage type of this variant is not QVariant::Invalid; otherwise returns FALSE.
.SH "QValueListConstIterator<QVariant> QVariant::listBegin () const"
Returns an iterator to the first item in the list if the variant's type is appropriate, or else a null iterator.
.SH "QValueListConstIterator<QVariant> QVariant::listEnd () const"
Returns the end iterator for the list if the variant's type is appropriate, or else a null iterator.
.SH "QMapConstIterator<QString, QVariant> QVariant::mapBegin () const"
Returns an iterator to the first item in the map, if the variant's type is appropriate, or else a null iterator.
.SH "QMapConstIterator<QString, QVariant> QVariant::mapEnd () const"
Returns the end iterator for the map, if the variant's type is appropriate, or else a null iterator.
.SH "QMapConstIterator<QString, QVariant> QVariant::mapFind ( const QString & key ) const"
Returns an iterator to the item in the map with \fIkey\fR as key, if the variant's type is appropriate and \fIkey\fR is a valid key, or else a null iterator.
.SH "Type QVariant::nameToType ( const char * name )\fC [static]\fR"
Converts the string representation of the storage type gven in \fIname\fR, to its enum representation.
.PP
If the string representation cannot be converted to any enum representation, the variant is set to Invalid.
.SH "bool QVariant::operator!= ( const QVariant & v ) const"
Compares this QVariant with \fIv\fR and returns TRUE if they are not equal; otherwise returns FALSE.
.SH "QVariant & QVariant::operator= ( const QVariant & variant )"
Assigns the value of the variant \fIvariant\fR to this variant.
.PP
This is a deep copy of the variant, but note that if the variant holds an explicitly shared type such as QImage, a shallow copy is performed.
.SH "bool QVariant::operator== ( const QVariant & v ) const"
Compares this QVariant with \fIv\fR and returns TRUE if they are equal; otherwise returns FALSE.
.SH "QValueListConstIterator<QString> QVariant::stringListBegin () const"
Returns an iterator to the first string in the list if the variant's type is StringList, or else a null iterator.
.SH "QValueListConstIterator<QString> QVariant::stringListEnd () const"
Returns the end iterator for the list if the variant's type is StringList, or else a null iterator.
.SH "const QBitArray QVariant::toBitArray () const"
Returns the variant as a QBitArray if the variant has type() BitArray, or an empty bitarray otherwise.
.PP
See also asBitArray().
.SH "const QBitmap QVariant::toBitmap () const"
Returns the variant as a QBitmap if the variant has type() Bitmap, or a null QBitmap otherwise.
.PP
See also asBitmap().
.SH "bool QVariant::toBool () const"
Returns the variant as a bool if the variant has type() Bool.
.PP
Returns TRUE if the variant has type Int, UInt or Double and its value is non-zero; otherwise returns FALSE.
.PP
See also asBool().
.SH "const QBrush QVariant::toBrush () const"
Returns the variant as a QBrush if the variant has type() Brush, or a default brush (with all black colors) otherwise.
.PP
See also asBrush().
.SH "const QByteArray QVariant::toByteArray () const"
Returns the variant as a QByteArray if the variant has type() ByteArray, or an empty bytearray otherwise.
.PP
See also asByteArray().
.SH "const QCString QVariant::toCString () const"
Returns the variant as a QCString if the variant has type() CString or String, or a 0 otherwise.
.PP
See also asCString().
.SH "const QColor QVariant::toColor () const"
Returns the variant as a QColor if the variant has type() Color, or an invalid color otherwise.
.PP
See also asColor().
.SH "const QColorGroup QVariant::toColorGroup () const"
Returns the variant as a QColorGroup if the variant has type() ColorGroup, or a completely black color group otherwise.
.PP
See also asColorGroup().
.SH "const QCursor QVariant::toCursor () const"
Returns the variant as a QCursor if the variant has type() Cursor, or the default arrow cursor otherwise.
.PP
See also asCursor().
.SH "const QDate QVariant::toDate () const"
Returns the variant as a QDate if the variant has type() Date, DateTime or String, or an invalid date otherwise.
.PP
Note that if the type() is String an invalid date will be returned if the string cannot be parsed as an Qt::ISODate format date.
.PP
See also asDate().
.SH "const QDateTime QVariant::toDateTime () const"
Returns the variant as a QDateTime if the variant has type() DateTime or String, or an invalid date/time otherwise.
.PP
Note that if the type() is String an invalid date/time will be returned if the string cannot be parsed as an Qt::ISODate format date/time.
.PP
See also asDateTime().
.SH "double QVariant::toDouble ( bool * ok = 0 ) const"
Returns the variant as a double if the variant has type() String, CString, Double, Int, UInt, or Bool; or 0.0 otherwise.
.PP
If \fIok\fR is non-null, \fI*ok\fR is set to TRUE if the value could be converted to a double and FALSE otherwise.
.PP
See also asDouble().
.SH "const QFont QVariant::toFont () const"
Returns the variant as a QFont if the variant has type() Font, or the default font otherwise.
.PP
See also asFont().
.SH "const QIconSet QVariant::toIconSet () const"
Returns the variant as a QIconSet if the variant has type() IconSet, or an icon set of null pixmaps otherwise.
.PP
See also asIconSet().
.SH "const QImage QVariant::toImage () const"
Returns the variant as a QImage if the variant has type() Image, or a null image otherwise.
.PP
See also asImage().
.SH "int QVariant::toInt ( bool * ok = 0 ) const"
Returns the variant as an int if the variant has type() String, CString, Int, UInt, Double, Bool or KeySequence; or 0 otherwise.
.PP
If \fIok\fR is non-null, \fI*ok\fR is set to TRUE if the value could be converted to an int and FALSE otherwise.
.PP
See also asInt() and canCast().
.SH "const QKeySequence QVariant::toKeySequence () const"
Returns the variant as a QKeySequence if the variant has type() KeySequence, Int or String, or an empty key sequence otherwise.
.PP
Note that not all Ints and Strings are valid key sequences and in such cases an empty key sequence will be returned.
.PP
See also asKeySequence().
.SH "const QValueList<QVariant> QVariant::toList () const"
Returns the variant as a QValueList<QVariant> if the variant has type() List or StringList, or an empty list otherwise.
.PP
See also asList().
.SH "const QMap<QString, QVariant> QVariant::toMap () const"
Returns the variant as a QMap<QString,QVariant> if the variant has type() Map, or an empty map otherwise.
.PP
See also asMap().
.SH "const QPalette QVariant::toPalette () const"
Returns the variant as a QPalette if the variant has type() Palette, or a completely black palette otherwise.
.PP
See also asPalette().
.SH "const QPixmap QVariant::toPixmap () const"
Returns the variant as a QPixmap if the variant has type() Pixmap, or a null pixmap otherwise.
.PP
See also asPixmap().
.SH "const QPoint QVariant::toPoint () const"
Returns the variant as a QPoint if the variant has type() Point, or a point (0, 0) otherwise.
.PP
See also asPoint().
.SH "const QPointArray QVariant::toPointArray () const"
Returns the variant as a QPointArray if the variant has type() PointArray, or an empty QPointArray otherwise.
.PP
See also asPointArray().
.SH "const QRect QVariant::toRect () const"
Returns the variant as a QRect if the variant has type() Rect, or an empty rectangle otherwise.
.PP
See also asRect().
.SH "const QRegion QVariant::toRegion () const"
Returns the variant as a QRegion if the variant has type() Region, or an empty QRegion otherwise.
.PP
See also asRegion().
.SH "const QSize QVariant::toSize () const"
Returns the variant as a QSize if the variant has type() Size, or an invalid size otherwise.
.PP
See also asSize().
.SH "QSizePolicy QVariant::toSizePolicy () const"
Returns the variant as a QSizePolicy if the variant has type() SizePolicy, or an undefined (but legal) size policy otherwise.
.SH "const QString QVariant::toString () const"
Returns the variant as a QString if the variant has type() String, CString, ByteArray, Int, Uint, Bool, Double, Date, Time, or DateTime, or QString::null otherwise.
.PP
See also asString().
.SH "const QStringList QVariant::toStringList () const"
Returns the variant as a QStringList if the variant has type() StringList or List of a type that can be converted to QString, or an empty list otherwise.
.PP
See also asStringList().
.SH "const QTime QVariant::toTime () const"
Returns the variant as a QTime if the variant has type() Time, DateTime or String, or an invalid time otherwise.
.PP
Note that if the type() is String an invalid time will be returned if the string cannot be parsed as an Qt::ISODate format time.
.PP
See also asTime().
.SH "uint QVariant::toUInt ( bool * ok = 0 ) const"
Returns the variant as an unsigned int if the variant has type() String, CString, UInt, Int, Double, or Bool; or 0 otherwise.
.PP
If \fIok\fR is non-null, \fI*ok\fR is set to TRUE if the value could be converted to a uint and FALSE otherwise.
.PP
See also asUInt().
.SH "Type QVariant::type () const"
Returns the storage type of the value stored in the variant. Usually it's best to test with canCast() whether the variant can deliver the data type you are interested in.
.SH "const char * QVariant::typeName () const"
Returns the name of the type stored in the variant. The returned strings describe the C++ datatype used to store the data: for example, "QFont", "QString", or "QValueList<QVariant>". An Invalid variant returns 0.
.SH "const char * QVariant::typeToName ( Type typ )\fC [static]\fR"
Converts the enum representation of the storage type, \fItyp\fR, to its
string representation.

.SH "SEE ALSO"
.BR http://doc.trolltech.com/qvariant.html
.BR http://www.trolltech.com/faq/tech.html
.SH COPYRIGHT
Copyright 1992-2001 Trolltech AS, http://www.trolltech.com.  See the
license file included in the distribution for a complete license
statement.
.SH AUTHOR
Generated automatically from the source code.
.SH BUGS
If you find a bug in Qt, please report it as described in
.BR http://doc.trolltech.com/bughowto.html .
Good bug reports help us to help you. Thank you.
.P
The definitive Qt documentation is provided in HTML format; it is
located at $QTDIR/doc/html and can be read using Qt Assistant or with
a web browser. This man page is provided as a convenience for those
users who prefer man pages, although this format is not officially
supported by Trolltech. 
.P
If you find errors in this manual page, please report them to
.BR [e-mail] .
Please include the name of the manual page (qvariant.3qt) and the Qt
version (3.0.0).