Kivy/KivyMD多文件应用中的屏幕管理与模块化实现指南

from kivy.app import App
from kivy.lang import Builder
# 导入所有屏幕类，这将同时加载它们各自的KV规则
from screen_one import ScreenOne
from screen_two import ScreenTwo
# 如果有更多屏幕，继续导入
# from screen_three import ScreenThree 

# 定义主KV字符串，包含ScreenManager及其所有子屏幕
# 注意：这里只声明了屏幕的类型和名称，具体布局在各自的KV中定义
kv_root = """
ScreenManager:  # 这是应用的根部件，管理所有屏幕
    ScreenOne:
        name: 'one' # 屏幕的唯一标识符
    ScreenTwo:
        name: 'two'
    # ScreenThree: # 如果有ScreenThree，也在这里声明
    #    name: 'three'
"""

class MyScreensApp(App):
    def build(self):
        # 使用Builder加载主KV字符串，创建并返回ScreenManager实例
        return Builder.load_string(kv_root)

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

from kivy.lang import Builder
from kivy.uix.screenmanager import Screen
from kivy.metrics import dp # 用于适配不同分辨率

# 为ScreenOne定义KV规则
kv_screen_one = """
<ScreenOne>: # 注意：这里只定义了ScreenOne的规则，没有ScreenManager
    BoxLayout:
        orientation: 'vertical'
        Label:
            text: '这是屏幕一'
            font_size: '24sp'
        Button:
            size_hint_y: None
            height: dp(48)
            text: '切换到屏幕二'
            on_release: root.manager.current = 'two' # 通过manager切换到名为'two'的屏幕
            # 可以添加过渡动画
            # on_release: root.manager.transition.direction = 'left'; root.manager.current = 'two'
"""
# 加载当前屏幕的KV规则
Builder.load_string(kv_screen_one)

class ScreenOne(Screen):
    # 如果有ScreenOne特有的Python逻辑，可以写在这里
    pass

# 可选：为方便独立测试，可以在此文件内添加一个简单的App
if __name__ == '__main__':
    from kivy.app import App
    from kivy.uix.screenmanager import ScreenManager

    class TestScreenOneApp(App):
        def build(self):
            sm = ScreenManager()
            sm.add_widget(ScreenOne(name='one'))
            # 如果需要测试切换，可以添加其他屏幕
            # sm.add_widget(ScreenTwo(name='two'))
            return sm

    TestScreenOneApp().run()

from kivy.lang import Builder
from kivy.uix.screenmanager import Screen
from kivy.metrics import dp

# 为ScreenTwo定义KV规则
kv_screen_two = """
<ScreenTwo>:
    BoxLayout:
        orientation: 'vertical'
        canvas: # 示例：为屏幕添加背景色
            Color:
                rgb: .5, .7, .5
            Rectangle:
                size: self.size
                pos:self.pos
        Label:
            text: '这是屏幕二'
            font_size: '24sp'
        Button:
            size_hint_y: None
            height: dp(48)
            text: '返回屏幕一'
            on_release: root.manager.current = 'one' # 切换到名为'one'的屏幕
            # on_release: root.manager.transition.direction = 'right'; root.manager.current = 'one'
"""
# 加载当前屏幕的KV规则
Builder.load_string(kv_screen_two)

class ScreenTwo(Screen):
    pass