PyQt5信号和插槽'QObject没有属性'错误

Question

我一直试图找到一种方法来从主外部的Python线程更新GUI线程.sourceforge上的PyQt5文档有关于如何执行此操作的良好说明.但我仍然无法让事情发挥作用.

有没有一种很好的方法来解释交互式会话的以下输出？不应该有办法在这些对象上调用emit方法吗？

>>> from PyQt5.QtCore import QObject, pyqtSignal
>>> obj = QObject()
>>> sig = pyqtSignal()
>>> obj.emit(sig)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'QObject' object has no attribute 'emit'

和

>>> obj.sig.emit()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'QObject' object has no attribute 'sig'

和

>>> obj.sig = pyqtSignal()
>>> obj.sig.emit()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'PyQt5.QtCore.pyqtSignal' object has no attribute 'emit'

Answer 1

以下单词和代码在PyQt5文档中.

新信号只应在 QObject的子类中定义.它们必须是类定义的一部分,并且在定义类之后不能作为类属性动态添加.

from PyQt5.QtCore import QObject, pyqtSignal

class Foo(QObject):

    # Define a new signal called 'trigger' that has no arguments.
    trigger = pyqtSignal()

    def connect_and_emit_trigger(self):
        # Connect the trigger signal to a slot.
        self.trigger.connect(self.handle_trigger)

        # Emit the signal.
        self.trigger.emit()

    def handle_trigger(self):
        # Show that the slot has been called.

        print "trigger signal received"