QGraphicsOpacityEffect

Qt 5.9.0 Reference Documentation

QGraphicsOpacityEffect Class

The QGraphicsOpacityEffect class provides an opacity effect. 更多...

头文件:	#include <QGraphicsOpacityEffect>
qmake:	QT += widgets
开始支持版本:	Qt 4.6
基类:	QGraphicsEffect

所有的成员列表, 包括继承的成员

属性

opacity : qreal
opacityMask : QBrush

1 个属性继承自 QGraphicsEffect
1 个属性继承自 QObject

公有函数

	QGraphicsOpacityEffect(QObject *parent = Q_NULLPTR)
	~QGraphicsOpacityEffect()
qreal	opacity() const
QBrush	opacityMask() const

3 个公有函数继承自 QGraphicsEffect
32 个公有函数继承自 QObject

公有槽函数

void	setOpacity(qreal opacity)
void	setOpacityMask(const QBrush &mask)

2 个公有槽函数继承自 QGraphicsEffect
1 个公有槽函数继承自 QObject

信号

void	opacityChanged(qreal opacity)
void	opacityMaskChanged(const QBrush &mask)

1 个信号继承自 QGraphicsEffect
2 个信号继承自 QObject

重新实现的受保护函数

virtual void draw(QPainter *painter)

7 个受保护的函数继承自 QGraphicsEffect
9 个受保护的函数继承自 QObject

其他继承的成员

1 个公有变量继承自 QObject
10 个静态公有成员继承自 QObject
7 个受保护的函数继承自 QGraphicsEffect
9 个受保护的函数继承自 QObject
2 个受保护的变量继承自 QObject

详细描述

The QGraphicsOpacityEffect class provides an opacity effect.

An opacity effect renders the source with an opacity. This effect is useful for making the source semi-transparent, similar to a fade-in/fade-out sequence. The opacity can be modified using the setOpacity() function.

By default, the opacity is 0.7.

参见 QGraphicsDropShadowEffect, QGraphicsBlurEffect, and QGraphicsColorizeEffect.

属性

opacity : qreal

This property holds the opacity of the effect.

The value should be in the range of 0.0 to 1.0, where 0.0 is fully transparent and 1.0 is fully opaque.

By default, the opacity is 0.7.

访问函数:

qreal	opacity() const
void	setOpacity(qreal opacity)

Notifier signal:

void	opacityChanged(qreal opacity)

参见 setOpacityMask().

opacityMask : QBrush

This property holds the opacity mask of the effect.

An opacity mask allows you apply opacity to portions of an element.

For example:


  ...
  QLinearGradient alphaGradient(rect.topLeft(), rect.bottomLeft());
  alphaGradient.setColorAt(0.0, Qt::transparent);
  alphaGradient.setColorAt(0.5, Qt::black);
  alphaGradient.setColorAt(1.0, Qt::transparent);
  QGraphicsOpacityEffect *effect = new QGraphicsOpacityEffect;
  effect->setOpacityMask(alphaGradient);
  ...

There is no opacity mask by default.

访问函数:

QBrush	opacityMask() const
void	setOpacityMask(const QBrush &mask)

Notifier signal:

void	opacityMaskChanged(const QBrush &mask)

参见 setOpacity().

成员函数

QGraphicsOpacityEffect::QGraphicsOpacityEffect(QObject **parent* = Q_NULLPTR)

Constructs a new QGraphicsOpacityEffect instance. The parent parameter is passed to QGraphicsEffect's constructor.

QGraphicsOpacityEffect::~QGraphicsOpacityEffect()

Destroys the effect.

`[virtual protected]` void QGraphicsOpacityEffect::draw(QPainter **painter*)

重新实现 QGraphicsEffect::draw().

`[signal]` void QGraphicsOpacityEffect::opacityChanged(qreal opacity)

This signal is emitted whenever the effect's opacity changes. The opacity parameter holds the effect's new opacity.

Note: Notifier signal for property opacity.

`[signal]` void QGraphicsOpacityEffect::opacityMaskChanged(const QBrush &mask)

This signal is emitted whenever the effect's opacity mask changes. The mask parameter holds the effect's new opacity mask.

Note: Notifier signal for property opacityMask.

目录