Kivy开发求助：Python无法修改.kv文件中按钮文本

问题根源及修正步骤 #

1. 类初始化方法错误嵌套 #

原代码中__init__方法被错误嵌套在generate_word函数内部，导致类初始化逻辑完全未执行，self.words未定义，初始词汇生成也不会触发。
修正： 将__init__移到WordGame类顶层，作为类的直接方法，并在初始化时调用generate_word。

2. KV文件中控件ID的引号错误 #

KV文件里Label的id: "word_label"使用了引号，导致Python代码中self.ids.word_label无法找到该控件（ID名被当作带引号的字符串）。
修正： 改为id: word_label，去掉引号。

3. 正确按钮映射逻辑颠倒 #

原代码创建correct_button的字典是{按钮: 翻译文本}，却试图用正确翻译文本作为键取值，引发KeyError。
修正： 将字典改为{翻译文本: 按钮}，通过正确翻译文本找到对应按钮实例。

4. 重复调用词汇生成方法 #

check_translation中连续调用两次generate_word，导致刚显示对错结果就立刻刷新词汇，用户无法看到反馈。
修正： 先判断对错并显示提示，再通过Clock.schedule_once延迟调用generate_word，给用户留足查看结果的时间。

5. 缺失必要模块导入 #

原代码未导入random、kivy.uix.boxlayout.BoxLayout等必要模块，运行会报错。
修正： 在代码开头添加所有必要的导入语句。

修正后的完整代码 #

Python代码（.py） #

import random
from kivy.uix.boxlayout import BoxLayout
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.clock import Clock
from kivymd.app import MDApp

vocab = {
    "ability": ["schopnost", "cane", "chien"],
    "able": ["být schopen", "gatto", "chat"],
    "about": ["o", "maison", "casa"],
    "above": ["nad", "albero", "arbre"],
    "abroad": ["zahraničí", "libro", "livre"],
    "absorb": ["vstřebat", "assorbire", "absorber"],
    "abuse": ["zneužití", "abuso", "abus"],
    "accept": ["přijmout", "accettare", "accepter"],
}

class WordGame(BoxLayout):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        self.words = list(vocab.keys())
        self.generate_word()

    def generate_word(self):
        word = random.choice(self.words)
        translations = vocab[word].copy()
        random.shuffle(translations)
        self.ids.word_label.text = word
        self.ids.button1.text = translations[0]
        self.ids.button2.text = translations[1]
        self.ids.button3.text = translations[2]
        self.translation_to_button = {
            translations[0]: self.ids.button1,
            translations[1]: self.ids.button2,
            translations[2]: self.ids.button3
        }
        self.correct_translation = vocab[word][0]

    def check_translation(self, instance):
        if instance.text == self.correct_translation:
            self.ids.word_label.text = "Correct!"
        else:
            self.ids.word_label.text = f"Incorrect! Correct is: {self.correct_translation}"
        Clock.schedule_once(lambda dt: self.generate_word(), 1.5)
    
kv_files = ['splash.kv', 'login.kv', 'menu.kv', 'levelselect.kv', 'levelb1.kv', 'Charakter.kv', 'test.kv']

class Aplikace(MDApp):
    def build(self):
        global obraz
        obraz = ScreenManager()
        for file in kv_files:
            obraz.add_widget(Builder.load_file(file))
        self.theme_cls.theme_style = "Dark"
        self.theme_cls.primary_palette = "Blue"
        return obraz
    
    def on_start(self):
        Clock.schedule_once(self.login, 1)
    
    def login(self, *args):
        obraz.current = "login"
    
    def levelselect(self):
        obraz.current = "levelselect"
    
    def log(self):
        obraz.current = "menu"
    
    def Event(self):
        obraz.current = "splash"
    
    def levelb1(self):
        obraz.current = "levelb1"
    
    def Forum(self):
        obraz.current = "splash"
    
    def Friendlist(self):
        obraz.current = "splash"
    
    def Leaderboard(self):
        obraz.current = "splash"
    
    def Charakter(self):
        obraz.current = "charakter"
    
    def test(self):
        obraz.current = "test"

Aplikace().run()

KV代码（test.kv） #

<WordGame>:
    BoxLayout:
        orientation: "vertical"
        size_hint: 1, 1
        BoxLayout:
            size_hint_y: 0.2
        BoxLayout:
            orientation:"horizontal"
            canvas.before:
                Color:
                    rgba: 1, 0, 0, 1
                Rectangle:
                    pos: self.pos
                    size: self.size
            size_hint_x: 1
            size_hint_y: 0.4

            Label:
                id: word_label
                text: "Click the correct translation"
                font_size: "24sp"
                bold: True
                text_size: self.width, None
                pos_hint: {'center_x': 0.5,'center_y': 0.5}
                halign: "center"

        BoxLayout:
            orientation: "horizontal"
            canvas.before:
                Color:
                    rgba: 0, 1, 0, 1
                Rectangle:
                    pos: self.pos
                    size: self.size
            spacing: 10
            padding: 10

            Button:
                size_hint: 1, 0.4
                id: button1
                text: "Option 1"
                on_release: root.check_translation(self)
            Button:
                size_hint: 1, 0.4
                id: button2
                text: "Option 2"
                on_release: root.check_translation(self)
            Button:
                size_hint: 1, 0.4
                id: button3
                text: "Option 3"
                on_release: root.check_translation(self)

        BoxLayout:
            size_hint_y: 0.2

Screen:
    name: "test"
    WordGame:

内容的提问来源于stack exchange，提问作者Kaeru