Question

最近我和Kivy的Screenmanager有些问题。从switch_to类访问管理器时，我无法使用管理器的Screen方法。在Screen班级中：self.manager.switch_to会出错：AttributeError: 'NoneType' object has no attribute 'switch_to'。我有点绝望。下面产生错误的简单应用程序。

import kivy
kivy.require("1.9.1")

from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.screenmanager import ScreenManager, Screen

screen1 = True


class Screen1(Screen):
    def __init__(self, **kw):
        super(Screen1, self).__init__(**kw)
        self.add_widget(Label(text="Screen1"))


class Screen2(Screen):
    def __init__(self, **kw):
        super(Screen2, self).__init__(**kw)
        self.add_widget(Label(text="Screen2"))


class BlackMenu(Screen):
    def __init__(self, **kw):
        super(BlackMenu, self).__init__(**kw)
        if screen1:
            self.manager.switch_to(Screen1())


class MyApp(App):
    def build(self):
        mymanager = ScreenManager()
        mymanager.switch_to(BlackMenu(name="black"))
        return mymanager


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

Answer 1

尝试将屏幕管理器声明为screen1

下的全局变量

import kivy
kivy.require("1.9.1")

from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.screenmanager import ScreenManager, Screen

screen1 = True
screen_manager = ScreenManager()

然后在您的构建功能中添加您的屏幕，如：

def build(self):
    screen_manager.add_widget(Screen1(name='screen1'))
    screen_manager.add_widget(Screen2(name='screen2'))
    screen_manager.add_widget(BlackMenu(name='black_menu'))
    return screen_manager

然后在黑屏中你可以做到：

class BlackMenu(Screen):
def __init__(self, **kw):
    super(BlackMenu, self).__init__(**kw)
    if screen_manager.current == 'screen1':
        screen_manager.switch_to(Screen1())

但请记住，切换到屏幕会从screen_manager子项中删除该屏幕，因此您必须再次管理添加它。祝你好运

Kivy ScreenManager问题

1 个答案: