Python (kivy) 中 ScreenManager 和 Screen 的问题。我想从 Screenmanager 类调用 Screen 中的 def答案

【问题标题】：Problems with ScreenManager and Screen in Python (kivy). I want to call on def in Screen from the Screenmanager classPython (kivy) 中 ScreenManager 和 Screen 的问题。我想从 Screenmanager 类调用 Screen 中的 def
【发布时间】：2019-11-07 23:08:59
【问题描述】：

我正在尝试从 Screenmanager 类的 Screenmanager 调用 Screen 类中的 def，但我不能。

我想在调用 ScreenManager 后立即启动应用程序时制作一个框布局并在该框布局中放置一个按钮，因此它是默认屏幕。我想这样做，这样我就可以在按下按钮时使用 self.parent.current = 'Screen Name' 在多个屏幕之间切换

这里是代码

class Manager(ScreenManager):
    def __init__(self):
        self.add_widget(Scr1().make_button())
class Scr1(Screen):
    def __init__(self):
        self.layout = BoxLayout(orientation = 'vertical')
        self.button = Button(text='hello')
        self.layout.add_widget(self.button)
    def make_button(self, layout):
        return self.layout



class MainApp(App):
    def build(self):
        sm =Manager()
        s1 = Scr1()
        sm.add_widget=s1
        return sm

if __name__ == "__main__":
    MainApp().run()

这是我得到的错误


 Traceback (most recent call last):
   File "C:/Users/user/Desktop/CarsonMusic/Learn.py", line 43, in <module>
     MainApp().run()
   File "C:\Users\user\AppData\Local\Programs\Python\Python37-32\lib\site-packages\kivy\app.py", line 829, in run
     root = self.build()
   File "C:/Users/user/Desktop/CarsonMusic/Learn.py", line 37, in build
     sm =Manager()
   File "C:/Users/user/Desktop/CarsonMusic/Learn.py", line 24, in __init__
     self.add_widget(Scr1().make_button())
   File "C:\Users\user\AppData\Local\Programs\Python\Python37-32\lib\site-packages\kivy\uix\screenmanager.py", line 979, in add_widget
     'ScreenManager accepts only Screen widget.')
 kivy.uix.screenmanager.ScreenManagerException: ScreenManager accepts only Screen widget.

我知道我可能犯了一个愚蠢的错误，但有人可以帮助我吗？

【问题讨论】：

标签： python python-3.x kivy

【解决方案1】：

我解决了！我必须删除 Manager(ScreenManager) 类，添加“超级”，然后将布局小部件添加到 self

这是我的新代码：

class Scr1(Screen):
    def __init__(self, **kwargs):
        super (Scr1, self).__init__(**kwargs)

        self.layout = BoxLayout(orientation='vertical')
        self.button = Button(text='hello')
        self.button.bind(on_press=self.screen2)
        self.layout.add_widget(self.button)
        self.add_widget(self.layout)

    def screen2(self, *args):
        self.manager.current = 'screen2'

class Scr2(Screen):

    def __init__(self, **kwargs):
        super (Scr2,self).__init__(**kwargs)

        self.layout2 = BoxLayout(orientation='vertical')
        self.add_widget(self.layout2)
        self.button2 = Button(text='hello2')
        self.button2.bind(on_press=self.screen1)
        self.layout2.add_widget(self.button2)
    def screen1(self, *args):
        self.manager.current = 'screen1'

class MainApp(App):
    def build(self):
        sm= ScreenManager()
        screen1 = Scr1(name='screen1')
        screen2= Scr2(name='screen2')
        sm.add_widget(screen1)
        sm.add_widget(screen2)
        return sm

if __name__ == "__main__":
    MainApp().run()

【讨论】：