从字典创建 pyqtSignals

Question

好吧，我正在编写一个通过 Python 设计的软件，我将在 PyQt5 应用程序中过多地使用信号和槽。我想到了创建一个字典，其中所有信号都会进入，每个信号都有自己的密钥以便访问（或基本上将其连接到一个函数）。问题是我得到这个错误'AttributeError: 'PyQt5.QtCore.pyqtSignal' object has no attribute 'connect' 由于某种原因。我阅读了有关此错误的信息，发现我必须在构造函数外部声明信号才能使其正常工作，但不幸的是，这会打破我的想法，因此，我来到这里是为了让有人可以解决我的问题。

如果你还不明白，代码如下：

from PyQt5 import QtWidgets
from PyQt5.QtWidgets import QMainWindow
from PyQt5.QtCore import QRunnable, pyqtSlot, QThreadPool, QObject, pyqtSignal

class WorkerSignals(QObject):
    signals = {}

    def __init__(self, **kwargs):
        QObject.__init__(self)
        if (kwargs is not None):
            for key, value in kwargs.items():
                self.signals[key] = value

class Worker(QRunnable):
    def __init__(self, fn, *args, **kwargs):
        super(Worker, self).__init__()
        self.fn = fn
        self.args = args
        self.kwargs = kwargs

    @pyqtSlot()
    def run(self):
        self.fn(*self.args, **self.kwargs)

以及创建信号的示例：

worker_signals = WorkerSignals(result=pyqtSignal(str), error=pyqtSignal(str))
worker_signals.signals['result'].connect(self.on_receive_result)
worker_signals.signals['error'].connect(self.on_receive_error)

Answer 1

如docs所示：

A signal (specifically an unbound signal) is a class attribute. When a signal is referenced as an attribute of an instance of the class then PyQt5 automatically binds the instance to the signal in order to create a bound signal. [...]

因此，它不仅需要在构造函数外部声明，而且必须是静态属性，因为它用作创建属于实例的信号的原型。一种可能的解决方案是使用类型创建动态类:

from PyQt5 import QtCore

d = {
    "result": QtCore.pyqtSignal(str),
    "error": QtCore.pyqtSignal(str)
}

WorkerSignals = type("WorkerSignals", (QtCore.QObject,), d)

if __name__ == '__main__':
    import sys
    app = QtCore.QCoreApplication(sys.argv)
    worker_signals = WorkerSignals()

    def on_result(text):
        print("result:", text)

    def on_error(text):
        print("error:", text)

    worker_signals.result.connect(on_result)
    worker_signals.error.connect(on_error)

    def emit_result():
        worker_signals.result.emit(" 1+1=2 ")
    def emit_error():
        worker_signals.error.emit(" :( ")

    QtCore.QTimer.singleShot(1000, emit_result)
    QtCore.QTimer.singleShot(2000, emit_error)

    QtCore.QTimer.singleShot(3000, app.quit)
    sys.exit(app.exec_())

从字典创建 pyqtSignals

Create pyqtSignals from dictionary

python

pyqt

qobject

qt-signals

pyqt5