PyQt5 在哪个模块中找到了emit 方法? [英] PyQt5 in what module is the emit method found?

问题描述

有人为我运行此代码作为健全性检查会很有帮助.

Python 3.3.1(默认，2013 年 4 月 17 日，22:30:32)[GCC 4.7.3] 在 Linux 上输入帮助"、版权"、信用"或许可"以获取更多信息.>>>从 PyQt5.QtCore 导入 pyqtSignal>>>for i in dir(pyqtSignal):...如果我 == 'emit':...打印(真)...>>>

是否为其他人返回 true?请注意，从 PyQt4 导入 QObject:

<预><代码>>>>从 PyQt4.QtCore 导入 QObject>>>对于 dir(QObject) 中的 i:...如果我 == 'emit':...打印(真)...真的

解决方案

pyqtSignal 不是信号，它是用于创建信号的工厂函数，所以它当然没有 emit 属性.它只返回一个 descriptor，当绑定到 QObject 实例时将返回实际的信号对象.这意味着只有 bound 信号会有 emit 方法.

QObject.emit 方法是 pyqt 中引入新样式信号之前的遗留物，现在 已删除.只需在绑定信号上使用 emit 方法来发射它:

class SomeObject(QObject):someSignal = pyqtSignal(...)实例 = SomeObject()instance.someSignal.emit(值)

It would be helpful somebody run this code for me as a sanity check.

Python 3.3.1 (default, Apr 17 2013, 22:30:32) 
[GCC 4.7.3] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>from PyQt5.QtCore import pyqtSignal
>>>for i in dir(pyqtSignal):
...    if i == 'emit':
...         print(True)
...
>>>

Is true returned for anyone else? Note that with a QObject import from PyQt4:

>>> from PyQt4.QtCore import QObject
>>> for i in dir(QObject):
...     if i == 'emit':
...             print(True)
... 
True

解决方案

pyqtSignal is not a signal, it is a factory function for creating signals, so of course it doesn't have a emit attribute. It just returns a descriptor, which when bound to a QObject instance will return the actual signal object. That means only a bound signal will have an emit method.

The QObject.emit method is a relic from times before new style signals were introduced in pyqt, and now has been removed. Just use the emit method on the bound signal to emit it:

class SomeObject(QObject):
    someSignal = pyqtSignal(...)

instance = SomeObject()
instance.someSignal.emit(value)

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