如何在Kivy中点击按钮释放时重置整个猜数字应用？

要实现点击"Play Again"的Yes按钮时完全重置游戏（生成新随机数、恢复剩余猜测次数），咱们可以分两步来修改代码：

步骤1：给App类添加重置游戏的方法 #

原来的随机数和剩余次数只在App启动时初始化一次，所以重启游戏时不会更新。咱们新增一个reset_game方法，专门负责重置所有游戏状态，同时更新UI里的剩余次数显示：

class GuessingGameApp(App):
    def build(self):
        # 启动时先初始化一次游戏状态
        self.reset_game()
        return kv

    def reset_game(self):
        # 生成1-10之间的新随机数
        self.computer_num = random.randint(1, 10)
        self.random_num = str(self.computer_num)
        print(f"新随机数已生成：{self.random_num}")
        # 把剩余猜测次数重置回3次
        self.guesses_left = 3
        # 获取TimeToGuess页面的剩余次数标签，同步更新显示文本
        time_to_guess_screen = self.root.get_screen('time_to_guess')
        time_to_guess_screen.ids.guesses_left.text = f'Guesses Left: {self.guesses_left}'

注意：要把原来在类顶部定义的computer_num、random_num、guesses_left删掉，这些变量现在由reset_game方法来初始化和更新。

步骤2：修改KV文件里的"Play Again"按钮逻辑 #

在Winner和Loser页面的Yes按钮中，添加调用重置方法的操作，确保跳转页面之前先重置游戏状态：

Winner页面的Yes按钮修改： #

Button:
    text: 'Yes'
    on_release:
        app.reset_game()
        root.manager.current = 'guess_choice'
        root.manager.transition.duration = 0

Loser页面的Yes按钮修改： #

Button:
    text: 'Yes'
    on_press:
        app.reset_game()
        root.manager.current = 'guess_choice'
        root.manager.transition.duration = 0

完整修改后的Python代码 #

from kivy import *
import random
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen

class WannaPlay(Screen):
    pass
class Guesses(Screen):
    pass
class TimeToGuess(Screen):
    pass
class Winner(Screen):
    pass
class Loser(Screen):
    pass
class ScreenManage(ScreenManager):
    pass

kv = Builder.load_file('guessinggame.kv')

class GuessingGameApp(App):
    def build(self):
        self.reset_game()
        return kv

    def reset_game(self):
        self.computer_num = random.randint(1, 10)
        self.random_num = str(self.computer_num)
        print(f"新随机数已生成：{self.random_num}")
        self.guesses_left = 3
        time_to_guess_screen = self.root.get_screen('time_to_guess')
        time_to_guess_screen.ids.guesses_left.text = f'Guesses Left: {self.guesses_left}'

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

这样修改后，每次点击"Play Again"的Yes按钮，游戏都会生成新的随机数，把剩余猜测次数恢复到3次，同时UI里的剩余次数显示也会同步更新，完全回到初始游戏状态~

内容的提问来源于stack exchange，提问作者David Sorrell