QSizeF 類

QSizeF 類使用浮點精度定義 2D 對象的大小。 更多...

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

• 所有成員列錶，包括繼承成員
• QSizeF is part of 描繪類 .

公共函數

	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 )

靜態公共成員

QSizeF

fromCGSize (CGSize size )

相關非成員

(從 6.8 起) bool	qFuzzyCompare (const QSizeF & lhs , const QSizeF & rhs )
(從 6.8 起) bool	qFuzzyIsNull (const QSizeF & size )
bool	operator!= (const QSizeF & lhs , const QSizeF & rhs )
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 & lhs , const QSizeF & rhs )
QDataStream &	operator>> (QDataStream & stream , QSizeF & size )

詳細描述

大小的指定是通過 width () 和 height ()。可以在構造函數中設置它和改變使用 setWidth (), setHeight ()，或 scale () 函數，或使用算術運算符。也可以直接操縱尺寸通過檢索寬度和高度的引用使用 rwidth () 和 rheight () 函數。最後，可以交換寬度和高度使用 transpose () 函數。

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 () 函數返迴 true if either of the width and height is less than (or equal to) zero, while the isNull () 函數返迴 true 僅當寬度和高度兩者為 0 時。

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 () 函數返迴由此尺寸和給定尺寸保持的最小高度 寬度的尺寸。

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.

另請參閱 QSize , QPointF ，和 QRectF .

成員函數文檔編製

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

返迴尺寸産生自此尺寸的增長按 margins .

另請參閱 shrunkBy ().

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

返迴尺寸産生從此尺寸的收縮按 margins .

另請參閱 grownBy ().

[constexpr noexcept] QSizeF:: QSizeF ()

Constructs an invalid size.

另請參閱 isValid ().

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

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

另請參閱 toSize () 和 QSize::toSizeF ().

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

Constructs a size with the given finite width and height .

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

返迴尺寸，該尺寸保持最小寬度 高度，及給定 otherSize .

另請參閱 expandedTo () 和 scale ().

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

返迴的尺寸保持此尺寸的最大寬度 高度和給定 otherSize .

另請參閱 boundedTo () 和 scale ().

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

創建 QSizeF from size .

另請參閱 toCGSize ().

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

返迴高度。

另請參閱 width () 和 setHeight ().

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

返迴 true 若寬度和高度兩者任一 <= 0；否則返迴 false .

另請參閱 isNull () 和 isValid ().

[noexcept] bool QSizeF:: isNull () const

返迴 true 若寬度和高度兩者為 0.0 (忽略正負號)；否則返迴 false .

另請參閱 isValid () 和 isEmpty ().

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

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

另請參閱 isNull () 和 isEmpty ().

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

返迴高度的引用。

使用引用使直接操縱高度成為可能。例如：

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

另請參閱 rwidth () 和 setHeight ().

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

返迴寬度的引用。

使用引用使直接操縱寬度成為可能。例如：

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

另請參閱 rheight () 和 setWidth ().

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

把尺寸比例縮放到矩形采用給定 width and height ，根據指定 mode .

• 若 mode is Qt::IgnoreAspectRatio ，大小被設為 ( width , height ).
• 若 mode is Qt::KeepAspectRatio ，當前大小在內側被比例縮放為盡可能大的矩形按 ( width , height )，保留寬高比。
• 若 mode is Qt::KeepAspectRatioByExpanding ，當前大小在外側被比例縮放為盡可能小的矩形按 ( width , height )，保留寬高比。

範例：

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)
					

另請參閱 setWidth (), setHeight ()，和 scaled ().

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

這是重載函數。

把尺寸比例縮放到矩形采用給定 size ，根據指定 mode .

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

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

另請參閱 scale ().

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

這是重載函數。

Returns a size scaled to a rectangle with the given size s ，根據指定 mode .

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

Sets the height to the given finite height .

另請參閱 height (), rheight ()，和 setWidth ().

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

Sets the width to the given finite width .

另請參閱 width (), rwidth ()，和 setHeight ().

[noexcept] CGSize QSizeF:: toCGSize () const

創建 CGSize 從 QSizeF .

另請參閱 fromCGSize ().

[constexpr noexcept] 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.

另請參閱 QSizeF () 和 QSize::toSizeF ().

[noexcept] void QSizeF:: transpose ()

交換寬度和高度值。

另請參閱 setWidth (), setHeight ()，和 transposed ().

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

Returns the size with width and height values swapped.

另請參閱 transpose ().

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

返迴寬度。

另請參閱 height () 和 setWidth ().

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

這是重載函數。

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

另請參閱 scale ().

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

添加給定 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 noexcept] QSizeF &QSizeF:: operator-= (const QSizeF & size )

減去給定 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 )

這是重載函數。

寬度和高度兩者除以給定 divisor and returns a reference to the size. The divisor must not be either zero or NaN.

另請參閱 scale ().

相關非成員

[constexpr noexcept, since 6.8] bool qFuzzyCompare (const QSizeF & lhs , const QSizeF & rhs )

返迴 true if the size lhs is approximately equal to the size rhs ；否則返迴 false .

The sizes are considered approximately equal if their width and height are approximately equal.

該函數在 Qt 6.8 引入。

[constexpr noexcept, since 6.8] bool qFuzzyIsNull (const QSizeF & size )

返迴 true if both width and height of the size size are approximately equal to zero.

該函數在 Qt 6.8 引入。

[constexpr noexcept] bool operator!= (const QSizeF & lhs , const QSizeF & rhs )

返迴 true if lhs and rhs are sufficiently different; otherwise returns false .

警告： This function does not check for strict inequality; instead, it uses a fuzzy comparison to compare the sizes' extents.

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

這是重載函數。

乘以給定 size by the given finite factor and returns the result.

另請參閱 QSizeF::scale ().

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

這是重載函數。

乘以給定 size by the given finite factor and returns the result.

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

返迴和對於 s1 and s2 ；各分量分彆相加。

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

返迴 s2 減去 s1 ；分彆減去各分量。

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

這是重載函數。

除以給定 size 通過給定 divisor and returns the result. The divisor must not be either zero or NaN.

另請參閱 QSizeF::scale ().

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

寫入給定 size 到給定 stream 並返迴流引用。

另請參閱 序列化 Qt 數據類型 .

[constexpr noexcept] bool operator== (const QSizeF & lhs , const QSizeF & rhs )

返迴 true if lhs and rhs are approximately equal; otherwise returns false.

警告： This function does not check for strict equality; instead, it uses a fuzzy comparison to compare the sizes' extents.

另請參閱 qFuzzyCompare .

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

讀取大小從給定 stream 進給定 size 並返迴流引用。

另請參閱 序列化 Qt 數據類型 .

內容

1. 公共函數

2. 靜態公共成員

3. 相關非成員

4. 詳細描述