QGraphicsSceneEvent 类

The QGraphicsSceneEvent class provides a base class for all graphics view related events. 更多...

头：	#include <QGraphicsSceneEvent>
qmake:	QT += widgets
Since:	Qt 4.2
继承：	QEvent
继承者：	QGraphicsSceneContextMenuEvent , QGraphicsSceneDragDropEvent , QGraphicsSceneHelpEvent , QGraphicsSceneHoverEvent , QGraphicsSceneMouseEvent , QGraphicsSceneMoveEvent , QGraphicsSceneResizeEvent ，和 QGraphicsSceneWheelEvent

所有成员列表，包括继承成员

公共函数

virtual	~QGraphicsSceneEvent ()
QWidget *	widget () const

6 公共函数继承自 QEvent

保护变量

QScopedPointer<QGraphicsSceneEventPrivate>

d_ptr

额外继承成员

1 特性继承自 QEvent
1 静态公共成员继承自 QEvent

详细描述

The QGraphicsSceneEvent class provides a base class for all graphics view related events.

当 QGraphicsView 接收 Qt 鼠标、键盘及拖放事件 ( QMouseEvent , QKeyEvent , QDragEvent, etc.), it translates them into instances of QGraphicsSceneEvent subclasses and forwards them to the QGraphicsScene 由它显示。然后，场景将事件转发给相关项。

例如，当 QGraphicsView 接收 QMouseEvent of type MousePress as a response to a user click, the view sends a QGraphicsSceneMouseEvent 类型 GraphicsSceneMousePress to the underlying QGraphicsScene through its mousePressEvent() function. The default QGraphicsScene::mousePressEvent () implementation determines which item was clicked and forwards the event to QGraphicsItem::mousePressEvent ().

Subclasses such as QGraphicsSceneMouseEvent and QGraphicsSceneContextMenuEvent provide the coordinates from the original QEvent in screen, scene, and item coordinates (see screenPos() , scenePos() ，和 pos() ). The item coordinates are set by the QGraphicsScene before it forwards the event to the event to a QGraphicsItem . The mouse events also add the possibility to retrieve the coordinates from the last event received by the view (see lastScreenPos() , lastScenePos() ，和 lastPos() ).

另请参阅 QEvent .

成员函数文档编制

`[虚拟]` QGraphicsSceneEvent:: ~QGraphicsSceneEvent ()

销毁事件。

Returns the widget where the event originated, or 0 if the event originates from another application.

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