QRadialGradient 类

QRadialGradient class is used in combination with QBrush 以指定径向渐变笔刷。 更多...

头: #include <QRadialGradient>
qmake: QT += gui
继承: QGradient

公共函数

QRadialGradient ()
QRadialGradient (const QPointF & center , qreal radius , const QPointF & focalPoint )
QRadialGradient (qreal cx , qreal cy , qreal radius , qreal fx , qreal fy )
QRadialGradient (const QPointF & center , qreal radius )
QRadialGradient (qreal cx , qreal cy , qreal radius )
QRadialGradient (const QPointF & center , qreal centerRadius , const QPointF & focalPoint , qreal focalRadius )
QRadialGradient (qreal cx , qreal cy , qreal centerRadius , qreal fx , qreal fy , qreal focalRadius )
QPointF center () const
qreal centerRadius () const
QPointF focalPoint () const
qreal focalRadius () const
qreal radius () const
void setCenter (const QPointF & center )
void setCenter (qreal x , qreal y )
void setCenterRadius (qreal radius )
void setFocalPoint (const QPointF & focalPoint )
void setFocalPoint (qreal x , qreal y )
void setFocalRadius (qreal radius )
void setRadius (qreal radius )

详细描述

QRadialGradient class is used in combination with QBrush 以指定径向渐变笔刷。

Qt supports both simple and extended radial gradients.

Simple radial gradients interpolate colors between a focal point and end points on a circle surrounding it. Extended radial gradients interpolate colors between a focal circle and a center circle. Points outside the cone defined by the two circles will be transparent. For simple radial gradients the focal point is adjusted to lie inside the center circle, whereas the focal point can have any position in an extended radial gradient.

Outside the end points the gradient is either padded, reflected or repeated depending on the currently set spread 方法:

PadSpread (default) ReflectSpread RepeatSpread

The colors in a gradient is defined using stop points of the QGradientStop type, i.e. a position and a color. Use the QGradient::setColorAt () 或 QGradient::setStops () function to define the stop points. It is the gradient's complete set of stop points that describes how the gradient area should be filled. If no stop points have been specified, a gradient of black at 0 to white at 1 is used.

In addition to the functions inherited from QGradient QRadialGradient class provides the center (), focalPoint () 和 radius () functions returning the gradient's center, focal point and radius respectively.

另请参阅 QLinearGradient , QConicalGradient ,和 The Gradients Example .

成员函数文档编制

QRadialGradient:: QRadialGradient ()

Constructs a simple radial gradient with the center and focal point at (0, 0) with a radius of 1.

QRadialGradient:: QRadialGradient (const QPointF & center , qreal radius , const QPointF & focalPoint )

Constructs a simple radial gradient with the given center , radius and focalPoint .

注意: If the given focal point is outside the circle defined by the center point and radius , it will be re-adjusted to lie at a point on the circle where it intersects with the line from center to focalPoint .

另请参阅 QGradient::setColorAt () 和 QGradient::setStops ().

QRadialGradient:: QRadialGradient ( qreal cx , qreal cy , qreal radius , qreal fx , qreal fy )

Constructs a simple radial gradient with the given center ( cx , cy ), radius and focal point ( fx , fy ).

注意: If the given focal point is outside the circle defined by the center ( cx , cy ) and the radius it will be re-adjusted to the intersection between the line from the center to the focal point and the circle.

另请参阅 QGradient::setColorAt () 和 QGradient::setStops ().

QRadialGradient:: QRadialGradient (const QPointF & center , qreal radius )

Constructs a simple radial gradient with the given center , radius and the focal point in the circle center.

另请参阅 QGradient::setColorAt () 和 QGradient::setStops ().

QRadialGradient:: QRadialGradient ( qreal cx , qreal cy , qreal radius )

Constructs a simple radial gradient with the center at ( cx , cy ) and the specified radius . The focal point lies at the center of the circle.

另请参阅 QGradient::setColorAt () 和 QGradient::setStops ().

QRadialGradient:: QRadialGradient (const QPointF & center , qreal centerRadius , const QPointF & focalPoint , qreal focalRadius )

Constructs an extended radial gradient with the given center , centerRadius , focalPoint ,和 focalRadius .

该函数在 Qt 4.8 引入。

QRadialGradient:: QRadialGradient ( qreal cx , qreal cy , qreal centerRadius , qreal fx , qreal fy , qreal focalRadius )

Constructs an extended radial gradient with the given center ( cx , cy ), center radius, centerRadius , focal point, ( fx , fy ), and focal radius focalRadius .

该函数在 Qt 4.8 引入。

QPointF QRadialGradient:: center () const

Returns the center of this radial gradient in logical coordinates.

另请参阅 setCenter () 和 QGradient::stops ().

qreal QRadialGradient:: centerRadius () const

Returns the center radius of this radial gradient in logical coordinates.

该函数在 Qt 4.8 引入。

另请参阅 setCenterRadius () 和 QGradient::stops ().

QPointF QRadialGradient:: focalPoint () const

Returns the focal point of this radial gradient in logical coordinates.

另请参阅 setFocalPoint () 和 QGradient::stops ().

qreal QRadialGradient:: focalRadius () const

Returns the focal radius of this radial gradient in logical coordinates.

该函数在 Qt 4.8 引入。

另请参阅 setFocalRadius () 和 QGradient::stops ().

qreal QRadialGradient:: radius () const

Returns the radius of this radial gradient in logical coordinates.

相当于 centerRadius ()

另请参阅 setRadius () 和 QGradient::stops ().

void QRadialGradient:: setCenter (const QPointF & center )

Sets the center of this radial gradient in logical coordinates to center .

该函数在 Qt 4.2 引入。

另请参阅 center ().

void QRadialGradient:: setCenter ( qreal x , qreal y )

这是重载函数。

Sets the center of this radial gradient in logical coordinates to ( x , y ).

该函数在 Qt 4.2 引入。

另请参阅 center ().

void QRadialGradient:: setCenterRadius ( qreal radius )

Sets the center radius of this radial gradient in logical coordinates to radius

该函数在 Qt 4.8 引入。

另请参阅 centerRadius ().

void QRadialGradient:: setFocalPoint (const QPointF & focalPoint )

Sets the focal point of this radial gradient in logical coordinates to focalPoint .

该函数在 Qt 4.2 引入。

另请参阅 focalPoint ().

void QRadialGradient:: setFocalPoint ( qreal x , qreal y )

这是重载函数。

Sets the focal point of this radial gradient in logical coordinates to ( x , y ).

该函数在 Qt 4.2 引入。

另请参阅 focalPoint ().

void QRadialGradient:: setFocalRadius ( qreal radius )

Sets the focal radius of this radial gradient in logical coordinates to radius

该函数在 Qt 4.8 引入。

另请参阅 focalRadius ().

void QRadialGradient:: setRadius ( qreal radius )

Sets the radius of this radial gradient in logical coordinates to radius

相当于 setCenterRadius ()

该函数在 Qt 4.2 引入。

另请参阅 radius ().