QGraphicsSceneEvent 类

QGraphicsSceneEvent 类提供基类为所有图形视图相关事件。 更多...

头: #include <QGraphicsSceneEvent>
CMake: find_package(Qt6 REQUIRED COMPONENTS Widgets)
target_link_libraries(mytarget PRIVATE Qt6::Widgets)
qmake: QT += widgets
继承: QEvent
继承者:

QGraphicsSceneContextMenuEvent , QGraphicsSceneDragDropEvent , QGraphicsSceneHelpEvent , QGraphicsSceneHoverEvent , QGraphicsSceneMouseEvent , QGraphicsSceneMoveEvent , QGraphicsSceneResizeEvent ,和 QGraphicsSceneWheelEvent

公共函数

virtual ~QGraphicsSceneEvent ()
(从 6.2 起) quint64 timestamp () const
QWidget * widget () const

详细描述

QGraphicsView 接收 Qt 鼠标、键盘及拖放事件 ( QMouseEvent , QKeyEvent ,QDragEvent,等),它将它们翻译成 QGraphicsSceneEvent 子类实例并将它们转发给 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 of type 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

[virtual noexcept] QGraphicsSceneEvent:: ~QGraphicsSceneEvent ()

销毁事件。

[since 6.2] quint64 QGraphicsSceneEvent:: timestamp () const

Returns the timestamp of the original event, or 0 if the original event does not report a time stamp.

该函数在 Qt 6.2 引入。

QWidget *QGraphicsSceneEvent:: widget () const

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