QConicalGradient 类

The QConicalGradient class is used in combination with QBrush 以指定锥形渐变笔刷。 更多...

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

公共函数

QConicalGradient ()
QConicalGradient (const QPointF & center , qreal angle )
QConicalGradient (qreal cx , qreal cy , qreal angle )
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

The QConicalGradient class is used in combination with QBrush 以指定锥形渐变笔刷。

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 QConicalGradient 类提供 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 .

成员函数文档编制

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 ().

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 ( 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 ().

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 )

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 ().