python - PyQt5 对不从 QObject 继承的类中的信号的支持

Question

在“PyQt4 和 PyQt5 之间的差异”部分( http://pyqt.sourceforge.net/Docs/PyQt5/pyqt4_differences.html )中，我可以阅读以下行:

Unlike PyQt4, PyQt5 supports the definition of properties, signals and slots in classes not sub-classed from QObject (i.e. in mixins).

但是，在“信号和槽的支持”部分 ( http://pyqt.sourceforge.net/Docs/PyQt5/signals_slots.html )，我可以读到:

New signals should only be defined in sub-classes of QObject. They must be part of the class definition and cannot be dynamically added as class attributes after the class has been defined.

我是否误解了什么或者这两个句子相互矛盾？

Answer 1

注意in mixins部分。这意味着您可以执行以下操作:

from PyQt5.QtCore import pyqtSignal, QObject

class SignalMixin:
    sig = pyqtSignal()

class Obj(SignalMixin, QObject):
    pass

o = Obj()
o.sig.connect(lambda: print('foo'))
o.sig.emit()