python - Kivy 使用 kv 文件中的 ScreenManager

Question

我正在编写一个 kivy 程序/游戏。我以前也做过一个，不过总共只有一屏。我已经开始开发一个新程序，其中包含实现屏幕管理器的想法。我设法在 python 文件内构建了屏幕管理器，但它不适合我的长期使用，我想尝试一下屏幕管理器来自 .kv 文件。

任何指导将不胜感激，不确定我错过了什么。我查看了这个问题(Kivy - Screen Manager - Accessing attribute in other class)，并将我认为正确的内容拼凑在一起，但仍然无法加载屏幕 - 我觉得这是一个简单的答案，我很盲目......

main.py;

from kivy.app import App
from kivy.uix.screenmanager import ScreenManager, Screen, FadeTransition


class MenuScreen(Screen):
    pass

class NewGameScreen(Screen):
    pass

class LoadGameScreen(Screen):
    pass

class ASCIILifeApp(App):
    pass

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

ASCIILife.kv;

#: kivy 1.9
#: import ScreenManager kivy.uix.screenmanager.ScreenManager
#: import Screen kivy.uix.screenmanager.ScreenManager
#: import NewGameScreen screen
#: import LoadGameScreen screen

ScreenManager:
    id: screen_manager
    #transition: FadeTransition()
    MenuScreen:
        id: menu_screen
        name: 'MenuScreen'
        manager: 'screen_manager'
    NewGameScreen:
        id: newgame_screen
        name: 'NewGameScreen'
        manager: 'screen_manager'
    LoadGameScreen: 
        id: loadgame_screen
        name: 'LoadGameScreen'
        manager: 'screen_manager'

<MenuScreen>:
    BoxLayout:
        orientation: 'vertical'
        Label:
            text: 'ASCII Life'
            font_size: 50
        Button:
            text: 'New Game'
            font_size: 30
            on_release: app.root.current = 'newgame'
        Button:
            text: 'Load Game'
            font_size: 30
            on_release: app.root.current = 'loadgame'
        Button:
            text: 'Settings'
            font_size: 30
            on_release: app.root.current = 'something'
<NewGameScreen>:
    BoxLayout:
        orientation: 'vertical'
        BoxLayout:
            orientation: 'vertical'
            Label:
                text: 'Game Length in Days'
                font_size: 30
            BoxLayout:
                orientation: 'horizontal'
                ToggleButton:
                    text: '100'
                    state: 'down'
                    group: 'newgame_days'
                    font_size: 30
                ToggleButton:
                    text: '200'
                    group: 'newgame_days'
                    font_size: 30
            BoxLayout:
                orientation: 'horizontal'
                ToggleButton:
                    text: '365'
                    group: 'newgame_days'
                    font_size: 30
                ToggleButton:
                    text: '3650'
                    group: 'newgame_days'
                    font_size: 30
            ToggleButton:
                text: 'Unlimited'
                group: 'newgame_days'
                font_size: 30
        BoxLayout:
            orientation: 'vertical'
            size_hint: (1, .5)
            Label:
                text: 'Difficulty (Score Multiplier)'
                font_size: 30
            BoxLayout:
                orientation: 'horizontal'
                ToggleButton:
                    text: 'Easy (x1)'
                    state: 'down'
                    group: 'newgame_difficulty'
                    font_size: 30
                ToggleButton:
                    text: 'Medium (x2.5)'
                    group: 'newgame_difficulty'
                    font_size: 30
                ToggleButton:
                    text: 'Hard (x5)'
                    group: 'newgame_difficulty'
                    font_size: 30
<LoadGameScreen>:
    BoxLayout:
        orientation: 'vertical'
        Label:
            text: 'load a game'
            font_size: 30
        Widget:
            canvas:
                Ellipse:
                    pos: self.pos
                    size: self.size
        BoxLayout:
            Button:
                text: 'Menu'
                font_size: 30
                on_release: app.root.current = 'menu'
            Button:
                text: 'text'
                font_size: 30

编辑:截断的 kv 文件

Answer 1

答案是使用构建器来构建 kv 文件。知道这很简单。文件如下；

main.py

#!/usr/bin/kivy
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen, FadeTransition
from kivy.properties import ObjectProperty


class MenuScreen(Screen):
    pass

class NewGameScreen(Screen):
    pass

class LoadGameScreen(Screen):
    pass

class ScreenManager(ScreenManager):
    pass

buildKV = Builder.load_file("ASCIILife.kv")

class ASCIILifeApp(App):
    def build(self):
        return buildKV

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