我怎样才能使 textinput 成为 class 变量

Question

我正在尝试从另一个屏幕获取 TextInput 的文本。在下面的代码中，我可以获得文本，但我的项目有多个功能。所以我想如果我可以让 textinput 成为一个 class 变量，它会更容易编码。

示例代码：

.py

from kivy.app import App
from kivy.uix.screenmanager import Screen, ScreenManager
from kivy.uix.screenmanager import NoTransition
import requests


class MainPage(Screen):
    pass


class ExercisePage(Screen):

    def test(self):
        link = self.manager.get_screen('mainpage')
        a = requests.get(f'{link.ids.http.text}/gpio12On')

    def testt(self):
        link = self.manager.get_screen('mainpage')
        a = requests.get(f'{link.ids.http.text}/gpio12Off')


class MyApp(App):

    def build(self):
        global sm
        sm = ScreenManager(transition=NoTransition())
        sm.add_widget(MainPage(name='mainpage'))
        sm.add_widget(ExercisePage(name='exercisepage'))
        return sm


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

这里是 .kv 文件

<MainPage>
    FloatLayout:
        TextInput:
            id: http
            text: ""
            multiline: False
            size_hint: 0.5,0.05
            pos_hint: {"x": 0.3, "y": 0.8}
        Button:
            text:"Enter"
            size_hint: 0.1,0.06
            pos_hint: {"x": 0.82, "y": 0.795}
            on_release:
                app.root.current = "exercisepage"

<ExercisePage>
    FloatLayout:
        Button:
            text:"test"
            size_hint: 0.5,0.075
            pos_hint: {"x": 0.2, "top": 0.4}
            on_release:
                root.test()
        Button:
            text:"test2"
            size_hint: 0.5,0.075
            pos_hint: {"x": 0.2, "top": 0.5}
            on_release:
                root.testt()

我想做的是这样的：

class ExercisePage(Screen):
    link = self.manager.get_screen('mainpage')
    
    def test(self):
        a = requests.get(f'{self.link.ids.http.text}/gpio12On')

    def testt(self):
        a = requests.get(f'{self.link.ids.http.text}/gpio12Off')

Answer 1

如果您在 kv 文件中定义应用程序 root，则 ids 在该 root 规则中随处可用。然后你可以在 ExercisePage 中定义一个 ObjectProperty 来引用 TextInput text。下面是这样一个 kv 文件的样子：

ScreenManager:
    MainPage:
        name: 'mainpage'
        FloatLayout:
            TextInput:
                id: http
                text: ""
                multiline: False
                size_hint: 0.5,0.05
                pos_hint: {"x": 0.3, "y": 0.8}
            Button:
                text:"Enter"
                size_hint: 0.1,0.06
                pos_hint: {"x": 0.82, "y": 0.795}
                on_release:
                    app.root.current = "exercisepage"  # this could also be just root.current = "exercisepage"
    
    ExercisePage:
        id: escr
        link: http.text  # link to the TextInput text
        name: 'exercisepage'
        FloatLayout:
            Button:
                text:"test"
                size_hint: 0.5,0.075
                pos_hint: {"x": 0.2, "top": 0.4}
                on_release:
                    escr.test()  # changed to use id
            Button:
                text:"test2"
                size_hint: 0.5,0.075
                pos_hint: {"x": 0.2, "top": 0.5}
                on_release:
                    escr.testt()  # changed to use id

然后在 ExercisePage 中定义 ObjectProperty，并在方法中使用它：

class ExercisePage(Screen):
    link = ObjectProperty(None)

    def test(self):
        # link = self.manager.get_screen('mainpage')
        print(self.link)
        # a = requests.get(f'{link.ids.http.text}/gpio12On')

    def testt(self):
        # link = self.manager.get_screen('mainpage')
        print(self.link)
        # a = requests.get(f'{link.ids.http.text}/gpio12Off')

并且由于您在 kv 文件中定义了 root 小部件，因此您可以从 MyApp class 中完全消除 build() 方法。

我怎样才能使 textinput 成为 class 变量

How can i make textinput a class variable

python

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