我有一个带有许多 QGraphicsItem 的 QGraphicsScene。有些项目具有清除和重新绘制场景的按钮。
The problem is that the clear() method deletes the QButton (and its associated data structures) in the middle of a method call that uses those very data structures. Then, immediately after clear() returns, the calling method tries to access the now-deleted data (because it wasn't expecting to be deleted in the middle of its routine), and bang -- a crash. From here.
我找到了C++的解决方案here ，但是我使用的是 PySide，无法对 python 使用相同的解决方案。
按照我的代码操作:
class GraphicsComponentButtonItem(QtGui.QGraphicsItem):
def __init__(self, x, y, update_out):
super(GraphicsComponentButtonItem, self).__init__()
self.x = x
self.y = y
self.update_out = update_out
self.setPos(x, y)
self.createButton()
self.proxy = QtGui.QGraphicsProxyWidget(self)
self.proxy.setWidget(self.button)
def boundingRect(self):
return QtCore.QRectF(self.x, self.y, self.button.width(), self.button.height())
def paint(self, painter, option, widget):
# Paint same stuffs
def createButton(self):
self.button = QtGui.QPushButton()
self.button.setText('Clear')
self.button.clicked.connect(self.action_press)
def action_press(self):
# Run some things
self.update_out()
class QGraphicsViewButtons(QtGui.QGraphicsView):
def __init__(self, scene, parent=None):
QtGui.QGraphicsView.__init__(self, parent)
self.scene = scene
# It's called outside
def updateScene(self):
self.scene.clear()
self.scene.addItem(GraphicsComponentButtonItem(0, 0, self.updateScene))
self.scene.addItem(GraphicsComponentButtonItem(0, 50, self.updateScene))
self.scene.addItem(GraphicsComponentButtonItem(0, 100, self.updateScene))
最佳答案
以下C++代码的转换:
QObject::connect(button, SIGNAL(clicked()), scene, SLOT(clear()), Qt::QueuedConnection);
Python 是:
self.button.clicked.connect(self.scene().clear, QtCore.Qt.QueuedConnection)
关于python - 从其中一项的事件中清除 QGraphicsScene，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/48387136/