问题
I'm just learning PyQt and looking at the Signals and Slots mechanism. I'm a bit baffled by the verbose syntax. Why do we have:
self.connect(dial, SIGNAL("valueChanged(int)"), spinbox.setValue)
I would much prefer to write the following:
self.connect(dial.valueChanged, spinbox.setValue)
Can anyone tell me why the connect() syntax needs to be so explicit/verbose?
回答1:
You can use PyQt's new style signals which are less verbose:
self.connect(dial, SIGNAL("valueChanged(int)"), spinbox.setValue)
Becomes:
dial.valueChanged.connect(spinbox.setValue)
回答2:
Luper's answer is much better than this one, but for the sake of completeness...
The ugly "old style" syntax is an anachronism from the C++ world - just look at the syntax those guys have to work with! Yucky...
回答3:
An even shorter way is to assign the signal name to the function in the keyword arguments of the constructor e.g. QDial(valueChanged=spinbox.setValue). PyQt will automatically connect the valueChanged() signal to spinbox.setValue().
来源：https://stackoverflow.com/questions/50184839/typeerror-native-qt-signal-is-not-callable-when-i-try-to-convert-pyqt4-to-pyqt5