QSize Class

成员函数

QSize::QSize()

Constructs a size with an invalid width and height (i.e., isValid() returns false).

参见 isValid().

QSize::QSize(int width, int height)

Constructs a size with the given width and height.

参见 setWidth() and setHeight().

QSize QSize::boundedTo(const QSize &otherSize) const

Returns a size holding the minimum width and height of this size and the given otherSize.

参见 expandedTo() and scale().

QSize QSize::expandedTo(const QSize &otherSize) const

Returns a size holding the maximum width and height of this size and the given otherSize.

参见 boundedTo() and scale().

int QSize::height() const

Returns the height.

参见 width() and setHeight().

bool QSize::isEmpty() const

Returns true if either of the width and height is less than or equal to 0; otherwise returns false.

参见 isNull() and isValid().

bool QSize::isNull() const

Returns true if both the width and height is 0; otherwise returns false.

参见 isValid() and isEmpty().

bool QSize::isValid() const

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

参见 isNull() and isEmpty().

int &QSize::rheight()

Returns a reference to the height.

Using a reference makes it possible to manipulate the height directly. For example:

  QSize size(100, 10);
  size.rheight() += 5;

  // size becomes (100,15)

参见 rwidth() and setHeight().

int &QSize::rwidth()

Returns a reference to the width.

Using a reference makes it possible to manipulate the width directly. For example:

  QSize size(100, 10);
  size.rwidth() += 20;

  // size becomes (120,10)

参见 rheight() and setWidth().

void QSize::scale(int width, int height, Qt::AspectRatioMode mode)

Scales the size to a rectangle with the given width and height, according to the specified mode:

• If mode is Qt::IgnoreAspectRatio, the size is set to (width, height).
• If mode is Qt::KeepAspectRatio, the current size is scaled to a rectangle as large as possible inside (width, height), preserving the aspect ratio.
• If mode is Qt::KeepAspectRatioByExpanding, the current size is scaled to a rectangle as small as possible outside (width, height), preserving the aspect ratio.

Example:

  QSize t1(10, 12);
  t1.scale(60, 60, Qt::IgnoreAspectRatio);
  // t1 is (60, 60)

  QSize t2(10, 12);
  t2.scale(60, 60, Qt::KeepAspectRatio);
  // t2 is (50, 60)

  QSize t3(10, 12);
  t3.scale(60, 60, Qt::KeepAspectRatioByExpanding);
  // t3 is (60, 72)

参见 setWidth(), setHeight(), and scaled().

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

This is an overloaded function.

Scales the size to a rectangle with the given size, according to the specified mode.

QSize QSize::scaled(int width, int height, Qt::AspectRatioMode mode) const

Return a size scaled to a rectangle with the given width and height, according to the specified mode.

This function was introduced in Qt 5.0.

参见 scale().

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

This is an overloaded function.

Return a size scaled to a rectangle with the given size s, according to the specified mode.

This function was introduced in Qt 5.0.

void QSize::setHeight(int height)

Sets the height to the given height.

参见 rheight(), height(), and setWidth().

void QSize::setWidth(int width)

Sets the width to the given width.

参见 rwidth(), width(), and setHeight().

CGSize QSize::toCGSize() const

Creates a CGSize from a QSize.

This function was introduced in Qt 5.8.

参见 QSizeF::fromCGSize().

void QSize::transpose()

Swaps the width and height values.

参见 setWidth(), setHeight(), and transposed().

QSize QSize::transposed() const

Returns a QSize with width and height swapped.

This function was introduced in Qt 5.0.

参见 transpose().

int QSize::width() const

Returns the width.

参见 height() and setWidth().

QSize &QSize::operator*=(qreal factor)

This is an overloaded function.

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

Note that the result is rounded to the nearest integer.

参见 scale().

QSize &QSize::operator+=(const QSize &size)

Adds the given size to this size, and returns a reference to this size. For example:

  QSize s( 3, 7);
  QSize r(-1, 4);
  s += r;

  // s becomes (2,11)

QSize &QSize::operator-=(const QSize &size)

Subtracts the given size from this size, and returns a reference to this size. For example:

  QSize s( 3, 7);
  QSize r(-1, 4);
  s -= r;

  // s becomes (4,3)

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

This is an overloaded function.

Divides both the width and height by the given divisor, and returns a reference to the size.

Note that the result is rounded to the nearest integer.

参见 QSize::scale().