事件过滤器QGraphicsItem [英] Event filter on QGraphicsItem

问题描述

是否可以在 QGraphicsItem 上添加事件过滤器？ Eventfilter有一个参数，它给你一个 QObject ，但由于 QGraphicsItem 不是从

Is it possible to have an event filter on a QGraphicsItem? Eventfilter has a param that gives you a QObject, but since QGraphicsItem isn't derived from QObject, then how would it work?

推荐答案

编辑： QGraphicsItem :: installSceneEventFilter ，如@ Frank的回答中所建议。示例：

Use QGraphicsItem::installSceneEventFilter as suggested in @Frank's answer. Example:

QGraphicsScene scene;
QGraphicsEllipseItem *ellipse = scene.addEllipse(QRectF(-10, -10, 20, 20));
QGraphicsLineItem *line = scene.addLine(QLineF(-10, -10, 20, 20));
line->installSceneEventFilter(ellipse);
// line's events are filtered by ellipse's sceneEventFilter() function.
ellipse->installSceneEventFilter(line);
// ellipse's events are filtered by line's sceneEventFilter() function.

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The first thing that popped into my mind was this:

创建一个新类，源自 QGraphicsItem 和 QObject ，因为这些都是不相关的（只要看一下docs告诉我），你应该有你想要的。

Create a new class, derived from both QGraphicsItem and QObject, since these are unrelated (as far as a glance at the docs tells me), you should have what you wanted.

....但是后来我更仔细看了文档，发现QGraphicsObject，这可能是你想要的，它甚至已经有成员 eventFilter

.... But then I looked at the docs more closely and found QGraphicsObject, which is probably exactly what you want, it even already has the member eventFilter

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