Question

我有一些课程：

class Window(object):
    def __init__(self, name):
        self.wind_name = name
    def getWindowName(self):
        return 'wnd' + self.wind_name

class Control(object):
    def __init__(self, name, wnd):
        self.contrl_name = name
        setattr(self, 'getWindowName', wnd.getWindowName)
        setattr(self, 'wind_name', wnd.wind_name)
    def getControlName(self):
        return (self.getWindowName(), 'unk' + self.contrl_name)

class Button(Control):
    def __init__(self, name, wnd):
        super(Button, self).__init__(name, wnd)
    def getControlName(self):
        return (self.getWindowName(), 'btn' + self.contrl_name)

wnd = Window('MyApp')
btnOK = Button('OK', wnd)
btnOK.getControlName() # work ok., return ('wndMyApp', 'btnOK')
btnOK.wind_name = 'NewApp'
btnOK.getControlName() # does not work properly., return ('wndMyApp', 'btnOK')

如何从类Control的对象扩展类Button | Window以访问对象{{中的函数getWindowName和字段wind_name 1}}？

是否可以在类控件中创建字段btnOK，或在self.wnd = wnd中添加方法setWindowName？

我无法从班级Window继承班级Control！这不符合逻辑。

Answer 1

Python允许从多个类继承，即

class Button(Control, Window):
    ...

但在这种情况下，你应该确切地知道你在做什么（谈到Pythons Method Resolution Order（MRO））。我建议你阅读这本小书：Python Attributes and Methods。

Answer 2

您可以使用属性属性

class Window(object):
def __init__(self, name):
    self.wind_name = name

def getWindowName(self):
    return 'wnd' + self.wind_name

class Control(object):
    def __init__(self, name, wnd):
        self.contrl_name = name
        self.wnd = wnd
        setattr(self, 'getWindowName', wnd.getWindowName)

    def get_wind_name(self):
        return self.wnd.wind_name
    def set_wind_name(self, v):
        self.wnd.wind_name = v

    wind_name = property(get_wind_name, set_wind_name)
    def getControlName(self):
        return (self.getWindowName(), 'unk' + self.contrl_name)

class Button(Control):
    def __init__(self, name, wnd):
        super(Button, self).__init__(name, wnd)
    def getControlName(self):
        return (self.getWindowName(), 'btn' + self.contrl_name)

wnd = Window('MyApp')
btnOK = Button('OK', wnd)
print btnOK.getControlName() # work ok., return ('wndMyApp', 'btnOK')
btnOK.wind_name = 'NewApp'
print btnOK.getControlName()

从对象扩展类

2 个答案: