QConicalGradient 类

QConicalGradient 类用于组合 QBrush 以指定锥形渐变笔刷。更多...

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

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公共函数

	QConicalGradient (qreal cx , qreal cy , qreal angle )
	QConicalGradient (const QPointF & center , qreal angle )
	QConicalGradient ()
qreal	angle () const
QPointF	center () const
void	setAngle (qreal angle )
void	setCenter (const QPointF & center )
void	setCenter (qreal x , qreal y )

详细描述

Conical gradients interpolate interpolate colors counter-clockwise around a center point.

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 , the QConicalGradient class provides the angle () 和 center () functions returning the start angle and center of the gradient.

注意， setSpread () function has no effect for conical gradients. The reason is that the conical gradient is closed by definition, i.e. the conical gradient fills the entire circle from 0 - 360 degrees, while the boundary of a radial or a linear gradient can be specified through its radius or final stop points, respectively.

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

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QConicalGradient:: QConicalGradient ( qreal cx , qreal cy , qreal angle )

Constructs a conical gradient with the given center ( cx , cy ), starting the interpolation at the given angle . The angle must be specified in degrees between 0 and 360.

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

QConicalGradient:: QConicalGradient (const QPointF & center , qreal angle )

Constructs a conical gradient with the given center , starting the interpolation at the given angle 。 angle must be specified in degrees between 0 and 360.

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

QConicalGradient:: QConicalGradient ()

Constructs a conical with center at (0, 0) starting the interpolation at angle 0.

另请参阅 QGradient::setColorAt (), setCenter ()，和 setAngle ().

qreal QConicalGradient:: angle () const

Returns the start angle of the conical gradient in logical coordinates.

另请参阅 setAngle () 和 stops ().

QPointF QConicalGradient:: center () const

Returns the center of the conical gradient in logical coordinates.

另请参阅 setCenter () 和 stops ().

void QConicalGradient:: setAngle ( qreal angle )

设置 angle to be the start angle for this conical gradient in logical coordinates.

该函数在 Qt 4.2 引入。

另请参阅 angle ().

void QConicalGradient:: setCenter (const QPointF & center )

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

另请参阅 center ().

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

这是重载函数。

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

另请参阅 center ().