python - 在单独的 .kv (Kivy) 文件中定义的屏幕之间切换

Question

我曾经通过在单个 .kv 文件中定义所有内容(包括屏幕)来设法使多屏幕程序运行。

通过使用 root.current (在 .kv 文件中)或 self.root.current (在 Python 文件中)，我能够在屏幕之间切换。然而，一旦有多个屏幕包含许多小部件，.kv 文件就会变得非常大并且难以维护。

这次我尝试在单独的 .kv 文件中定义屏幕，但无法在屏幕之间进行切换。到目前为止，每次尝试都会导致错误(语法无效、屏幕名称未定义...)。

有没有办法在单独的 .kv 文件中定义的屏幕之间切换？ 以下是我正在使用的文件:

ma​​in.py

from kivy.app import App


class MainApp(App):
    pass


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

ma​​in.kv:

#:include screen_1.kv
#:include screen_2.kv

#:import NoTransition kivy.uix.screenmanager.NoTransition

ScreenManager:
    transition: NoTransition()


    Screen:
        name: "main_screen"

        BoxLayout:
            orientation: "vertical"

            Label:
                text: "main screen"
            Button:
                text: "to screen 1"
                on_press: app.root.current = "screen_1"
            Button:
                text: "to screen 2"
                on_press: app.root.current = "screen_2"

screen_1.kv:

Screen:
    name: 'screen_1'

    BoxLayout:
        orientation: "vertical"

        Label:
            text: "Screen 1"
        Button:
            text: "to main screen"
            on_press: app.root.current = "main_screen"
        Button:
            text: "to screen 2"
            on_press: app.root.current = "screen_2"

screen_2.kv:

Screen:
    name: 'screen_2'

    BoxLayout:
        orientation: "vertical"

        Label:
            text: "Screen 2"
        Button:
            text: "to main screen"
            on_press: app.root.current = "main_screen"
        Button:
            text: "to screen 1"
            on_press: app.root.current = "screen_1"

Answer 1

解决方案

1. 添加dynamic class进入screen_1.kv和screen_2.kv ，例如<Screen1@Screen>:和<Screen2@Screen>:分别。
2. 实例化屏幕，Screen1:和Screen2:在main.kv

示例

screen_1.kv

<Screen1@Screen>:
    name: 'screen_1'

    BoxLayout:
        orientation: "vertical"

        Label:
            text: "Screen 1"
        Button:
            text: "to main screen"
            on_press: app.root.current = "main_screen"
        Button:
            text: "to screen 2"
            on_press: app.root.current = "screen_2"

screen_2.kv

<Screen2@Screen>:
    name: 'screen_2'

    BoxLayout:
        orientation: "vertical"

        Label:
            text: "Screen 2"
        Button:
            text: "to main screen"
            on_press: app.root.current = "main_screen"
        Button:
            text: "to screen 1"
            on_press: app.root.current = "screen_1"

main.kv

#:include screen_1.kv
#:include screen_2.kv

#:import NoTransition kivy.uix.screenmanager.NoTransition


ScreenManager:
    transition: NoTransition()


    Screen:
        name: "main_screen"

        BoxLayout:
            orientation: "vertical"

            Label:
                text: "main screen"
            Button:
                text: "to screen 1"
                on_press: app.root.current = "screen_1"
            Button:
                text: "to screen 2"
                on_press: app.root.current = "screen_2"

    Screen1:

    Screen2:

输出