Kivy教程：深入理解按钮事件处理与if条件判断的陷阱

from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy.properties import NumericProperty

class Team:
    def __init__(self, team_name):
        self.team_name = team_name
        self._fouls = 0 # 内部变量，通常通过属性访问
        self.players = []

    @property
    def fouls(self):
        return self._fouls

    @fouls.setter
    def fouls(self, value):
        self._fouls = value

class Player:
    def __init__(self, name):
        self.name = name
        self.stats = {
            "Fouls": 0,
            "2-pt FG MADE": 0,
            "2-pt FG Missed": 0,
            "Rebounds": 0,
            "Assists": 0,
        }

# ... (HeaderRowWidget 保持不变)
class HeaderRowWidget(GridLayout):
    def __init__(self, **kwargs):
        super(HeaderRowWidget, self).__init__(**kwargs)
        self.cols = 6
        self.add_widget(Label(text="Player Name"))
        self.add_widget(Label(text="Shirt Number"))
        self.add_widget(Label(text="Fouls"))
        self.add_widget(Label(text="2-pt FG MADE"))
        self.add_widget(Label(text="2-pt FG Missed"))
        self.add_widget(Label(text="Rebounds"))

class MyRowWidget(GridLayout):
    def __init__(self, player, team_instance, **kwargs):
        super(MyRowWidget, self).__init__(**kwargs)
        self.cols = 6
        self.player = player
        self.name_label = Label(text=player.name)
        self.shirt_number_label = Label(text="default")
        self.add_widget(self.name_label)
        self.add_widget(self.shirt_number_label)
        self.team_instance = team_instance

        button_labels = ["Fouls", "2-pt FG MADE", "2-pt FG Missed", "Rebounds"]
        self.buttons = {}

        for label in button_labels:
            button = Button(text="+") # 注意：所有按钮的文本都是 "+"
            self.buttons[label] = button
            button.bind(on_press=self.update_stats)
            self.add_widget(button)

    def update_stats(self, instance):
        # 原始的、存在问题的逻辑
        button_text = instance.text.strip()  # 获取被按下按钮的文本

        if button_text == "Fouls":  # 试图根据按钮文本判断
            self.player.stats["Fouls"] += 1
            print("players fouls increased")
            self.team_instance.fouls += 1 # 访问Team的fouls属性
            print("teams fouls increased")
        else:
            # 当if条件不满足时，进入else分支，并通过遍历来识别按钮
            for label, button in self.buttons.items():
                if button == instance:
                    self.player.stats[label] += 1
                    print(f"stat '{label}' updated for player")
                    break # 找到后退出循环

# ... (Kivy App 和 RootWidget 的定义，此处省略以聚焦核心问题)

for label in button_labels:
    button = Button(text="+") # 关键点：所有按钮文本均为 "+"
    self.buttons[label] = button
    # ...

    def update_stats(self, instance):
        # 直接比较触发事件的按钮实例与存储的特定按钮实例
        if instance == self.buttons["Fouls"]:  # 判断是否是“犯规”按钮对象
            self.player.stats["Fouls"] += 1
            print(f"Player fouls increased: {self.player.stats['Fouls']}")
            self.team_instance.fouls += 1 # 访问Team的fouls属性
            print(f"Team fouls increased: {self.team_instance.fouls}")
        else:
            # 对于其他按钮，通过遍历找到对应的统计标签
            for label, button in self.buttons.items():
                if button == instance:
                    self.player.stats[label] += 1
                    print(f"Player stat '{label}' updated: {self.player.stats[label]}")
                    break # 找到后即可退出循环

class MyRowWidget(GridLayout):
    def __init__(self, player, team_instance, **kwargs):
        super(MyRowWidget, self).__init__(**kwargs)
        self.cols = 6
        self.player = player
        self.name_label = Label(text=player.name)
        self.shirt_number_label = Label(text="default")
        self.add_widget(self.name_label)
        self.add_widget(self.shirt_number_label)
        self.team_instance = team_instance

        button_labels = ["Fouls", "2-pt FG MADE", "2-pt FG Missed", "Rebounds"]
        self.buttons = {}

        for label in button_labels:
            button = Button(text="+")
            button.stat_label = label # <--- 添加这一行：为按钮实例添加自定义属性
            self.buttons[label] = button
            button.bind(on_press=self.update_stats)
            self.add_widget(button)

    def update_stats(self, instance):
        # 直接访问按钮的自定义属性来识别其功能
        stat_type = getattr(instance, 'stat_label', None) # 安全地获取自定义属性

        if stat_type == "Fouls":
            self.player.stats["Fouls"] += 1
            print(f"Player fouls increased: {self.player.stats['Fouls']}")
            self.team_instance.fouls += 1 # 访问Team的fouls属性
            print(f"Team fouls increased: {self.team_instance.fouls}")
        elif stat_type: # 确保stat_type存在且不为None
            self.player.stats[stat_type] += 1
            print(f"Player stat '{stat_type}' updated: {self.player.stats[stat_type]}")
        else:
            print("Unknown button pressed or missing 'stat_label' attribute.")