python - QGraphicsScene 鼠标事件

Question

我正在使用 QGraphicsScene 类。如何检测鼠标离开 QGraphicsScene ？是否有任何内部函数可以实现此目的？

Answer 1

如果您想检测释放事件，您必须覆盖 mouseReleaseEvent()方法:

from PyQt5 import QtCore, QtGui, QtWidgets


class GraphicsScene(QtWidgets.QGraphicsScene):
    def mouseReleaseEvent(self, event):
        print(event.scenePos())
        super().mouseReleaseEvent(event)


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)

    scene = GraphicsScene()
    w = QtWidgets.QGraphicsView(scene)
    w.resize(640, 480)
    w.show()

    sys.exit(app.exec_())

更新:

QGraphicsScene 本身不是一个允许检测何时离开它的元素，因为它可以是多个 QGraphicsView 的一部分，您必须做的是检测何时离开 QGraphicsView 覆盖 leaveEvent()方法:

from PyQt5 import QtCore, QtGui, QtWidgets


class GraphicsView(QtWidgets.QGraphicsView):
    def enterEvent(self, event):
        print("enter")
        super().enterEvent(event)

    def leaveEvent(self, event):
        print("leave")
        super().leaveEvent(event)


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)

    scene = QtWidgets.QGraphicsScene()
    w = GraphicsView(scene)
    w.resize(640, 480)
    w.show()

    sys.exit(app.exec_())