QSizeF 类

QSizeF 类使用浮点精度定义 2D 对象的大小。更多...

头：	#include <QSizeF>
CMake:	find_package(Qt6 REQUIRED COMPONENTS Core) target_link_libraries(mytarget PRIVATE Qt6::Core)
qmake:	QT += core

所有成员列表，包括继承成员
QSizeF is part of 描绘类 .

公共函数

	QSizeF ()
	QSizeF (const QSize & size )
	QSizeF (qreal width , qreal height )
QSizeF	boundedTo (const QSizeF & otherSize ) const
QSizeF	expandedTo (const QSizeF & otherSize ) const
QSizeF	grownBy (QMarginsF margins ) const
qreal	height () const
bool	isEmpty () const
bool	isNull () const
bool	isValid () const
qreal &	rheight ()
qreal &	rwidth ()
void	scale (qreal width , qreal height , Qt::AspectRatioMode mode )
void	scale (const QSizeF & size , Qt::AspectRatioMode mode )
QSizeF	scaled (qreal width , qreal height , Qt::AspectRatioMode mode ) const
QSizeF	scaled (const QSizeF & s , Qt::AspectRatioMode mode ) const
void	setHeight (qreal height )
void	setWidth (qreal width )
QSizeF	shrunkBy (QMarginsF margins ) const
CGSize	toCGSize () const
QSize	toSize () const
void	transpose ()
QSizeF	transposed () const
qreal	width () const
QSizeF &	*operator=** (qreal factor )
QSizeF &	operator+= (const QSizeF & size )
QSizeF &	operator-= (const QSizeF & size )
QSizeF &	operator/= (qreal divisor )

静态公共成员

QSizeF

fromCGSize (CGSize size )

bool	operator!= (const QSizeF & s1 , const QSizeF & s2 )
QSizeF	operator* (const QSizeF & size , qreal factor )
QSizeF	operator* (qreal factor , const QSizeF & size )
QSizeF	operator+ (const QSizeF & s1 , const QSizeF & s2 )
QSizeF	operator- (const QSizeF & s1 , const QSizeF & s2 )
QSizeF	operator/ (const QSizeF & size , qreal divisor )
QDataStream &	operator<< (QDataStream & stream , const QSizeF & size )
bool	operator== (const QSizeF & s1 , const QSizeF & s2 )
QDataStream &	operator>> (QDataStream & stream , QSizeF & size )

详细描述

大小的指定是通过 width () 和 height ()。可以在构造函数中设置它和改变使用 setWidth (), setHeight ()，或 scale () 函数，或使用算术运算符。也可以直接操纵尺寸通过检索宽度和高度的引用使用 rwidth () 和 rheight () 函数。最后，可以交换宽度和高度使用 transpose () 函数。

The isValid () function determines if a size is valid. A valid size has both width and height greater than or equal to zero. The isEmpty () 函数返回 true if either of the width and height is less than (or equal to) zero, while the isNull () 函数返回 true 仅当宽度和高度两者为 0 时。

使用 expandedTo () function to retrieve a size which holds the maximum height and width of this size and a given size. Similarly, the boundedTo () 函数返回由此尺寸和给定尺寸保持的最小高度宽度的尺寸。

The QSizeF class also provides the toSize () function returning a QSize copy of this size, constructed by rounding the width and height to the nearest integers.

QSizeF objects can be streamed as well as compared.

另请参阅 QSize , QPointF ，和 QRectF .

成员函数文档编制

`[constexpr]` QSizeF QSizeF:: grownBy ( QMarginsF margins ) const

返回尺寸产生自此尺寸的增长按 margins .

另请参阅 shrunkBy ().

`[constexpr]` QSizeF QSizeF:: shrunkBy ( QMarginsF margins ) const

返回尺寸产生从此尺寸的收缩按 margins .

另请参阅 grownBy ().

`[constexpr]` QSizeF:: QSizeF ()

Constructs an invalid size.

另请参阅 isValid ().

`[constexpr]` QSizeF:: QSizeF (const QSize & size )

Constructs a size with floating point accuracy from the given size .

另请参阅 toSize () 和 QSize::toSizeF ().

`[constexpr]` QSizeF:: QSizeF ( qreal width , qreal height )

Constructs a size with the given finite width and height .

`[constexpr]` QSizeF QSizeF:: boundedTo (const QSizeF & otherSize ) const

返回尺寸，该尺寸保持最小宽度高度，及给定 otherSize .

另请参阅 expandedTo () 和 scale ().

`[constexpr]` QSizeF QSizeF:: expandedTo (const QSizeF & otherSize ) const

返回的尺寸保持此尺寸的最大宽度高度和给定 otherSize .

另请参阅 boundedTo () 和 scale ().

`[static]` QSizeF QSizeF:: fromCGSize ( CGSize size )

创建 QRectF from size .

另请参阅 toCGSize ().

`[constexpr]` qreal QSizeF:: height () const

返回高度。

另请参阅 width () 和 setHeight ().

`[constexpr]` bool QSizeF:: isEmpty () const

返回 true 若宽度和高度两者任一 <= 0；否则返回 false .

另请参阅 isNull () 和 isValid ().

bool QSizeF:: isNull () const

返回 true 若宽度和高度两者为 0.0 (忽略正负号)；否则返回 false .

另请参阅 isValid () 和 isEmpty ().

`[constexpr]` bool QSizeF:: isValid () const

返回 true if both the width and height are equal to or greater than 0; otherwise returns false .

另请参阅 isNull () 和 isEmpty ().

`[constexpr]` qreal &QSizeF:: rheight ()

返回高度的引用。

使用引用使直接操纵高度成为可能。例如：

QSizeF size(100, 10.2);
size.rheight() += 5.5;
// size becomes (100,15.7)

另请参阅 rwidth () 和 setHeight ().

`[constexpr]` qreal &QSizeF:: rwidth ()

返回宽度的引用。

使用引用使直接操纵宽度成为可能。例如：

QSizeF size(100.3, 10);
size.rwidth() += 20.5;
 // size becomes (120.8,10)

另请参阅 rheight () 和 setWidth ().

void QSizeF:: scale ( qreal width , qreal height , Qt::AspectRatioMode mode )

把尺寸比例缩放到矩形采用给定 width and height ，根据指定 mode .

若 mode is Qt::IgnoreAspectRatio ，尺寸被设为 ( width , height ).
若 mode is Qt::KeepAspectRatio , the current size is scaled to a rectangle as large as possible inside ( width , height ), preserving the aspect ratio.
若 mode is Qt::KeepAspectRatioByExpanding , the current size is scaled to a rectangle as small as possible outside ( width , height ), preserving the aspect ratio.

范例：

QSizeF t1(10, 12);
t1.scale(60, 60, Qt::IgnoreAspectRatio);
// t1 is (60, 60)
QSizeF t2(10, 12);
t2.scale(60, 60, Qt::KeepAspectRatio);
// t2 is (50, 60)
QSizeF t3(10, 12);
t3.scale(60, 60, Qt::KeepAspectRatioByExpanding);
// t3 is (60, 72)

另请参阅 setWidth (), setHeight ()，和 scaled ().

void QSizeF:: scale (const QSizeF & size , Qt::AspectRatioMode mode )

这是重载函数。

把尺寸比例缩放到矩形采用给定 size ，根据指定 mode .

QSizeF QSizeF:: scaled ( qreal width , qreal height , Qt::AspectRatioMode mode ) const

Returns a size scaled to a rectangle with the given width and height ，根据指定 mode .

另请参阅 scale ().

QSizeF QSizeF:: scaled (const QSizeF & s , Qt::AspectRatioMode mode ) const

这是重载函数。

Returns a size scaled to a rectangle with the given size s ，根据指定 mode .

`[constexpr]` void QSizeF:: setHeight ( qreal height )

Sets the height to the given finite height .

另请参阅 height (), rheight ()，和 setWidth ().

`[constexpr]` void QSizeF:: setWidth ( qreal width )

Sets the width to the given finite width .

另请参阅 width (), rwidth ()，和 setHeight ().

CGSize QSizeF:: toCGSize () const

创建 CGSize 从 QSizeF .

另请参阅 fromCGSize ().

`[constexpr]` QSize QSizeF:: toSize () const

Returns an integer based copy of this size.

Note that the coordinates in the returned size will be rounded to the nearest integer.

另请参阅 QSizeF () 和 QSize::toSizeF ().

void QSizeF:: transpose ()

交换宽度和高度值。

另请参阅 setWidth (), setHeight ()，和 transposed ().

`[constexpr]` QSizeF QSizeF:: transposed () const

Returns the size with width and height values swapped.

另请参阅 transpose ().

`[constexpr]` qreal QSizeF:: width () const

返回宽度。

另请参阅 height () 和 setWidth ().

`[constexpr]` QSizeF &QSizeF:: operator= ( qreal factor* )

这是重载函数。

Multiplies both the width and height by the given finite factor and returns a reference to the size.

另请参阅 scale ().

`[constexpr]` QSizeF &QSizeF:: operator+= (const QSizeF & size )

添加给定 size to this size and returns a reference to this size. For example:

QSizeF s( 3, 7);
QSizeF r(-1, 4);
s += r;
// s becomes (2,11)

`[constexpr]` QSizeF &QSizeF:: operator-= (const QSizeF & size )

减去给定 size from this size and returns a reference to this size. For example:

QSizeF s( 3, 7);
QSizeF r(-1, 4);
s -= r;
// s becomes (4,3)

QSizeF &QSizeF:: operator/= ( qreal divisor )

这是重载函数。

Divides both the width and height by the given divisor and returns a reference to the size. The divisor must not be either zero or NaN.

另请参阅 scale ().

QSizeF 类

公共函数

静态公共成员

相关非成员

详细描述

成员函数文档编制

[constexpr] QSizeF QSizeF:: grownBy ( QMarginsF margins ) const

[constexpr] QSizeF QSizeF:: shrunkBy ( QMarginsF margins ) const

[constexpr] QSizeF:: QSizeF ()

[constexpr] QSizeF:: QSizeF (const QSize & size )

[constexpr] QSizeF:: QSizeF ( qreal width , qreal height )

[constexpr] QSizeF QSizeF:: boundedTo (const QSizeF & otherSize ) const

[constexpr] QSizeF QSizeF:: expandedTo (const QSizeF & otherSize ) const

[static] QSizeF QSizeF:: fromCGSize ( CGSize size )

[constexpr] qreal QSizeF:: height () const

[constexpr] bool QSizeF:: isEmpty () const

bool QSizeF:: isNull () const

[constexpr] bool QSizeF:: isValid () const

[constexpr] qreal &QSizeF:: rheight ()

[constexpr] qreal &QSizeF:: rwidth ()

void QSizeF:: scale ( qreal width , qreal height , Qt::AspectRatioMode mode )

void QSizeF:: scale (const QSizeF & size , Qt::AspectRatioMode mode )

QSizeF QSizeF:: scaled ( qreal width , qreal height , Qt::AspectRatioMode mode ) const

QSizeF QSizeF:: scaled (const QSizeF & s , Qt::AspectRatioMode mode ) const

[constexpr] void QSizeF:: setHeight ( qreal height )

[constexpr] void QSizeF:: setWidth ( qreal width )

CGSize QSizeF:: toCGSize () const

[constexpr] QSize QSizeF:: toSize () const

void QSizeF:: transpose ()

[constexpr] QSizeF QSizeF:: transposed () const

[constexpr] qreal QSizeF:: width () const

[constexpr] QSizeF &QSizeF:: operator*= ( qreal factor )

[constexpr] QSizeF &QSizeF:: operator+= (const QSizeF & size )

[constexpr] QSizeF &QSizeF:: operator-= (const QSizeF & size )

QSizeF &QSizeF:: operator/= ( qreal divisor )

相关非成员

[constexpr] bool operator!= (const QSizeF & s1 , const QSizeF & s2 )

[constexpr] QSizeF operator* (const QSizeF & size , qreal factor )

[constexpr] QSizeF operator* ( qreal factor , const QSizeF & size )

[constexpr] QSizeF operator+ (const QSizeF & s1 , const QSizeF & s2 )

[constexpr] QSizeF operator- (const QSizeF & s1 , const QSizeF & s2 )

QSizeF operator/ (const QSizeF & size , qreal divisor )

QDataStream & operator<< ( QDataStream & stream , const QSizeF & size )

[constexpr] bool operator== (const QSizeF & s1 , const QSizeF & s2 )

QDataStream & operator>> ( QDataStream & stream , QSizeF & size )

内容

`[constexpr]` QSizeF QSizeF:: grownBy ( QMarginsF margins ) const

`[constexpr]` QSizeF QSizeF:: shrunkBy ( QMarginsF margins ) const

`[constexpr]` QSizeF:: QSizeF ()

`[constexpr]` QSizeF:: QSizeF (const QSize & size )

`[constexpr]` QSizeF:: QSizeF ( qreal width , qreal height )

`[constexpr]` QSizeF QSizeF:: boundedTo (const QSizeF & otherSize ) const

`[constexpr]` QSizeF QSizeF:: expandedTo (const QSizeF & otherSize ) const

`[static]` QSizeF QSizeF:: fromCGSize ( CGSize size )

`[constexpr]` qreal QSizeF:: height () const

`[constexpr]` bool QSizeF:: isEmpty () const

`[constexpr]` bool QSizeF:: isValid () const

`[constexpr]` qreal &QSizeF:: rheight ()

`[constexpr]` qreal &QSizeF:: rwidth ()

`[constexpr]` void QSizeF:: setHeight ( qreal height )

`[constexpr]` void QSizeF:: setWidth ( qreal width )

`[constexpr]` QSize QSizeF:: toSize () const

`[constexpr]` QSizeF QSizeF:: transposed () const

`[constexpr]` qreal QSizeF:: width () const

`[constexpr]` QSizeF &QSizeF:: operator= ( qreal factor* )

`[constexpr]` QSizeF &QSizeF:: operator+= (const QSizeF & size )

`[constexpr]` QSizeF &QSizeF:: operator-= (const QSizeF & size )

`[constexpr]` bool operator!= (const QSizeF & s1 , const QSizeF & s2 )

`[constexpr]` QSizeF operator* (const QSizeF & size , qreal factor )

`[constexpr]` QSizeF operator* ( qreal factor , const QSizeF & size )

`[constexpr]` QSizeF operator+ (const QSizeF & s1 , const QSizeF & s2 )

`[constexpr]` QSizeF operator- (const QSizeF & s1 , const QSizeF & s2 )

`[constexpr]` bool operator== (const QSizeF & s1 , const QSizeF & s2 )