android - 如何使用 kivy StringProperty？

Question

我想实现一个 kivy 应用程序，它有两个屏幕(由屏幕管理器管理)。在第一个屏幕(称为 LoginScreen)上有两个 TextInput 字段和一个按钮。在第二个屏幕上，我有两个标签，我想显示在第一个屏幕上输入的值。单击按钮后更改屏幕。
我设法将这些字段绑定(bind)在一起，以便在第二个屏幕上显示值。但是，我想在第二个屏幕中“处理”这些值，不幸的是，我没能做到。
我所说的“处理”是指，我想使用自定义构建的类(正在运行)登录我的电子邮件帐户并列出我看不见的电子邮件(由该类的一个功能提供) 在一个 kivy 列表中。
有人可以告诉我如何获取输入的值并使用它们来创建我的类吗？
如果有任何帮助，我将不胜感激!
我的.py文件:

from kivy.app import App
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.properties import ListProperty, StringProperty

class MainScreenManager(ScreenManager):
    pass

class LoginScreen(Screen):
    entered_email_address = StringProperty('')
    entered_password = StringProperty('')

    def check_input(self):
        text_input_email = self.ids['ti_email'].text
        text_input_password = self.ids['ti_password'].text

        self.entered_email_address = text_input_email
        self.entered_password = text_input_password

        """
        the values in this part are printed out
        print self.manager
        print self.manager.screens
        print self.manager.get_screen('HomeScreen').email_address
        print self.manager.get_screen('HomeScreen').password
        """

        self.manager.current = 'HomeScreen'

class HomeScreen(Screen):
    email_address = StringProperty()
    password = StringProperty()

    def __init__(self, *args, **kwargs):
        super(HomeScreen, self).__init__(*args, **kwargs)

class TutorialApp(App):

    def build(self):
        return MainScreenManager()


if __name__ == '__main__':
    TutorialApp().run()

我的 .kv 文件:

<MainScreenManager>:
    id: screen_manager

    LoginScreen:
        id: login_screen
        name: 'LoginScreen'
        manager: screen_manager

    HomeScreen:
        id: home_screen
        name: 'HomeScreen'
        email_address: login_screen.entered_email_address
        password: login_screen.entered_password

<LoginScreen>
    BoxLayout:
        orientation: 'vertical'
        TextInput:
            id: ti_email
            multiline: False
            size_hint_y: None
            height: 40
            font_size: 25

        TextInput:
            id: ti_password
            multiline: False
            size_hint_y: None
            height: 40
            font_size: 25

        Button:
            id: btn_login
            text: 'Login!'
            height: 100
            width: 150
            on_press:
                root.check_input()

<HomeScreen>
    BoxLayout:
        orientation: 'vertical'
        Label:
            text: root.email_address

        Label:
            text: root.password

Answer 1

根据评论部分的要求，我创建了一个在不使用 kv lang 的情况下在小部件之间绑定(bind)属性的示例。请记住，这可能不是实现目标的最佳方式，因为在这里使用 kv lang 会更容易。

from kivy.app import App
from kivy.uix.screenmanager import Screen, ScreenManager
from kivy.properties import StringProperty, ObjectProperty
from kivy.clock import mainthread
from kivy.lang import Builder

gui = '''
MyScreenManager

    HomeScreen
        name: 'home'

    LoginScreen
        name: 'login'


<HomeScreen>
    nickname_input: nickname_input
    nickname: nickname_input.text

    BoxLayout:
        TextInput
            id: nickname_input
        Button
            on_press: root.manager.current = 'login'

<LoginScreen>

    BoxLayout:
        Label
            text: root.nickname
        Button
            on_press: root.manager.current = 'home'
'''


class HomeScreen(Screen):
    nickname_input = ObjectProperty()
    nickname = StringProperty()


class LoginScreen(Screen):
    nickname = StringProperty()


class MyScreenManager(ScreenManager):

    def __init__(self, *args, **kwargs):
        super(MyScreenManager, self).__init__(*args, **kwargs)

        @mainthread
        def delayed():
            home_screen = self.get_screen('home')
            login_screen = self.get_screen('login')

            home_screen.bind(nickname=login_screen.setter('nickname'))
        delayed()


class Test(App):

    def build(self):
        return Builder.load_string(gui)

Test().run()