PyQt事件,当变量值更改时 [英] PyQt Event when a variable value is changed
问题描述
我有一个变量t
t = 0
无论何时更改t值,我都想开始一个事件. 如何 ?没有valuechanged.connect属性或任何变量...
I want to start an event whenever t value is changed. How ? There's no valuechanged.connect properties or anything for variables...
推荐答案
对于全局变量,仅使用赋值是不可能的.但是对于属性来说,它非常简单:只需使用属性(或 __getattr__/__setattr__
).这样可以有效地将赋值转换为函数调用,使您可以添加所需的任何其他行为:
For a global variable, this is not possible using assignment alone. But for an attribute it is quite simple: just use a property (or maybe __getattr__/__setattr__
). This effectively turns assignment into a function call, allowing you to add whatever additional behaviour you like:
class Foo(QWidget):
valueChanged = pyqtSignal(object)
def __init__(self, parent=None):
super(Foo, self).__init__(parent)
self._t = 0
@property
def t(self):
return self._t
@t.setter
def t(self, value):
self._t = value
self.valueChanged.emit(value)
现在您可以执行foo = Foo(); foo.t = 5
,并且在更改值之后将发出信号.
Now you can do foo = Foo(); foo.t = 5
and the signal will be emitted after the value has changed.
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