内容

• 公共函数
• 详细描述

QFontInfo 类

QFontInfo class provides general information about fonts. 更多...

头：	#include <QFontInfo>
qmake:	QT += gui

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注意： 此类的所有函数 可重入 .

公共函数

	QFontInfo (const QFont & font )
	QFontInfo (const QFontInfo & fi )
	~QFontInfo ()
bool	bold () const
bool	exactMatch () const
QString	family () const
bool	fixedPitch () const
bool	italic () const
int	pixelSize () const
int	pointSize () const
qreal	pointSizeF () const
QFont::Style	style () const
QFont::StyleHint	styleHint () const
QString	styleName () const
void	swap (QFontInfo & other )
int	weight () const
QFontInfo &	operator= (const QFontInfo & fi )

详细描述

QFontInfo class provides general information about fonts.

QFontInfo class provides the same access functions as QFont ，如 family (), pointSize (), italic (), weight (), fixedPitch (), styleHint () etc. But whilst the QFont access functions return the values that were set, a QFontInfo object returns the values that apply to the font that will actually be used to draw the text.

For example, when the program asks for a 25pt Courier font on a machine that has a non-scalable 24pt Courier font, QFont will (normally) use the 24pt Courier for rendering. In this case, QFont::pointSize () returns 25 and QFontInfo::pointSize () returns 24.

There are three ways to create a QFontInfo 对象。

1. Calling the QFontInfo constructor with a QFont creates a font info object for a screen-compatible font, i.e. the font cannot be a printer font. If the font is changed later, the font info object is not 更新。

   (Note: If you use a printer font the values returned may be inaccurate. Printer fonts are not always accessible so the nearest screen font is used if a printer font is supplied.)

2. QWidget::fontInfo () returns the font info for a widget's font. This is equivalent to calling QFontInfo (widget-> font ()). If the widget's font is changed later, the font info object is not 更新。
3. QPainter::fontInfo () returns the font info for a painter's current font. If the painter's font is changed later, the font info object is not 更新。

另请参阅 QFont , QFontMetrics ，和 QFontDatabase .

成员函数文档编制

QFontInfo:: QFontInfo (const QFont & font )

构造字体信息对象为 font .

The font must be screen-compatible, i.e. a font you use when drawing text in widgets or pixmaps , not QPicture or QPrinter .

The font info object holds the information for the font that is passed in the constructor at the time it is created, and is not updated if the font's attributes are changed later.

使用 QPainter::fontInfo () to get the font info when painting. This will give correct results also when painting on paint device that is not screen-compatible.

QFontInfo:: QFontInfo (const QFontInfo & fi )

构造副本为 fi .

QFontInfo:: ~QFontInfo ()

销毁字体信息对象。

bool QFontInfo:: bold () const

返回 true if weight () would return a value greater than QFont::Normal ；否则返回 false .

另请参阅 weight () 和 QFont::bold ().

bool QFontInfo:: exactMatch () const

返回 true if the matched window system font is exactly the same as the one specified by the font; otherwise returns false .

另请参阅 QFont::exactMatch ().

QString QFontInfo:: family () const

Returns the family name of the matched window system font.

另请参阅 QFont::family ().

bool QFontInfo:: fixedPitch () const

Returns the fixed pitch value of the matched window system font.

另请参阅 QFont::fixedPitch ().

bool QFontInfo:: italic () const

Returns the italic value of the matched window system font.

另请参阅 QFont::italic ().

int QFontInfo:: pixelSize () const

Returns the pixel size of the matched window system font.

另请参阅 QFont::pointSize ().

int QFontInfo:: pointSize () const

Returns the point size of the matched window system font.

另请参阅 pointSizeF () 和 QFont::pointSize ().

qreal QFontInfo:: pointSizeF () const

Returns the point size of the matched window system font.

另请参阅 QFont::pointSizeF ().

QFont::Style QFontInfo:: style () const

Returns the style value of the matched window system font.

另请参阅 QFont::style ().

QFont::StyleHint QFontInfo:: styleHint () const

Returns the style of the matched window system font.

Currently only returns the style hint set in QFont .

另请参阅 QFont::styleHint () 和 QFont::StyleHint .

QString QFontInfo:: styleName () const

Returns the style name of the matched window system font on systems that support it.

该函数在 Qt 4.8 引入。

另请参阅 QFont::styleName ().

void QFontInfo:: swap ( QFontInfo & other )

Swaps this font info instance with other 。此函数非常快，且从不失败。

该函数在 Qt 5.0 引入。

int QFontInfo:: weight () const

Returns the weight of the matched window system font.

另请参阅 QFont::weight () 和 bold ().

QFontInfo &QFontInfo:: operator= (const QFontInfo & fi )

Assigns the font info in fi .