Kivy MDDataTable中instance_table.row_data更新异常问题

初始问题 #

开发简单计分卡应用时，在获取更新后的单元格值环节遇到以下问题：

• 通过create_table方法创建表格时，column_sums打印的列值正常（为包含'0'的元组列表）。
• 打开弹窗更新表格数值后，界面显示已更新，但调用update_cell函数通过instance_table.row_data访问表格数据时，仍输出包含'0'的元组列表，界面新值未同步到该数据集合中。
• 尝试复用create_table中的逻辑重新计算column_sums，结果依旧是包含'0'的元组列表。
• 直接更新CellRow的text属性是否错误？未找到名为value的属性。

初始代码 #

class Example(MDApp):
    dialog = None
    text_field = None

    def build(self):
        kv = Builder.load_string(KV)
        self.theme_cls.theme_style = "Light"
        self.sm = WindowManager()

        screens = [LandingWindow(name="landing"), NewGameWindow(name="new_game"), ScorecardWindow(name="scorecard"),]
        for screen in screens:
            self.sm.add_widget(screen)

        self.sm.current = "landing" #set to "landing"
        return self.sm

    def button_pressed(self, *args):
        for a in args:
            try:
                self.text_field.text += a.text
            except:
                pass

    def update_cell(self, instance_row, instance_table, text_field, *args):
        instance_row.text = text_field.text
        print(instance_table.row_data)


    def close(self):
        Example.get_running_app().sm.current = "landing"
        #TODO delete the data from the page

    def open_popup(self, instance_table, instance_row):
        box = BoxLayout(orientation="vertical")
        self.text_field = TextInput(size_hint_y=0.25)
        box.add_widget(self.text_field)
        grid = GridLayout(cols=3)
        numeric_keypad = ['7', '8', '9', '4', '5', '6', '1', '2', '3', '.', '0', 'OK']
        for x in numeric_keypad:
            if str(x) == 'OK':
                ok_button = Button(text=str(x))
                grid.add_widget(ok_button)
            else:
                number_button = Button(text=str(x))
                number_button.bind(on_release=self.button_pressed)
                grid.add_widget(number_button)
        box.add_widget(grid)
        popup = Popup(title="Enter Your Score", content=box, size_hint=(0.5,0.5))
        ok_button.bind(on_release=lambda *args: self.update_cell(instance_row, instance_table, self.text_field, *args), on_press=popup.dismiss)
        popup.open()

    def create_table(self):
        game_name = self.root.get_screen("new_game").ids['game_name'].text
        rounds = self.root.get_screen("new_game").ids['rounds'].value
        players = self.root.get_screen("new_game").ids['players'].value
        players = int(players)
        rounds = int(rounds)
        round_list = [("0",) * players for _ in range(rounds)]
        table = MDDataTable(
            rows_num=len(round_list),
            column_data=[(f"Player {x + 1}", dp(20)) for x in range(players)],
            row_data=round_list,
            on_row_press = self.open_popup
        )
        column_sums = [sum(int(row_data[column_index]) for row_data in table.row_data) for column_index in
                       range(players)]
        table.bind(on_row_press=self.open_popup)
        self.root.get_screen("scorecard").ids['add_table_to_scrollview'].add_widget(table)
        self.sm.current = "scorecard"

        print(column_sums)


Example().run()

更新后的问题 #

调整代码后，表格数据（界面显示及column_sums打印的元组列表）已能同步更新，但出现新问题：代码会按固定顺序更新单元格索引，从[0]（第一个单元格）开始。例如，选中第14个单元格时，实际更新的是第一个单元格；选中第5个单元格时，实际更新的是第二个单元格。

更新后的update_cell函数代码 #

def update_cell(self, instance_row, instance_table, text_field, *args):
    #instance_row.text = text_field.text # This updates the correct cell and appears on the screen but isn't actually updating the values in the list of tuples.

    print("row clicked is: ", instance_row)
    # Split the instance_row.text into individual elements
    row_text_elements = instance_row.text.split(',')

    # Find the row_index corresponding to instance_row.text
    row_index = -1
    for index, row_data in enumerate(instance_table.row_data):
        if all(element in row_data for element in row_text_elements):
            row_index = index
            break

    if row_index != -1:
        # Find the cell_index corresponding to instance_row.text
        cell_index = -1
        row_data_list = list(instance_table.row_data[row_index])
        for index, element in enumerate(row_data_list):
            if element == instance_row.text:
                cell_index = index
                break

        if cell_index != -1:
            # Update the cell value in the row
            row_data_list[cell_index] = text_field.text
            instance_table.row_data[row_index] = tuple(row_data_list)
            print("row index: ", instance_table.row_data[row_index])

内容的提问来源于stack exchange，提问作者Callum