如何在按钮单击时重置屏幕内容？ Python, Kivy

Question

请帮我弄清楚。

我目前正在处理的程序计算已售商品的数量。

在 DailyWindow 屏幕上，该程序显示了售出物品的一般数量和总收入，一切正常。

在 TotalWindow 屏幕上，程序应将项目的临时数量及其成本显示为一个订单。 按下删除按钮后，程序必须删除此屏幕的内容才能显示下一个新订单。

我不知道如何重置 TotalWindow 屏幕和价格计数器的全部内容。

对不起我的英语，提前谢谢！

主要.py：

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


class TotalWindow(Screen):

    def on_pre_enter(self, *args):
        
        coffee = self.manager.ids.coffee.clickCounter
        tea = self.manager.ids.tea.clickCounter

        big_dict = {**coffee, **tea}

        self.coffee_price = self.manager.ids.coffee.total_counter
        self.tea_price = self.manager.ids.tea.total_counter

        self.set_label_text(big_dict, self.ids.label1)

    def delete_total(self):
        #how is this function need to work ?
        pass


    def set_label_text(self, counts, label):

        label.text = ""
        for item_name, count in counts.items():
            label.text += f"{item_name} ({count[0]})\n"

        label.text += "\nTotal Price: " + str(self.coffee_price + self.tea_price)


class DailyWindow(Screen):

    def on_pre_enter(self, *args):
        
        coffee = self.manager.ids.coffee.clickCounter
        tea = self.manager.ids.tea.clickCounter

        self.coffee_price = self.manager.ids.coffee.daily_counter
        self.tea_price = self.manager.ids.tea.daily_counter

        self.set_label_text(coffee, self.ids.label1)
        self.set_label_text(tea, self.ids.label2)

        self.total_price(self.ids.label3)

    def set_label_text(self, counts, label):

        label.text = ""
        for item_name, count in counts.items():
            label.text += f"{item_name}:  {count[0]}\n"

    def total_price(self, label):

        label.text = "Total: " + str(self.coffee_price + self.tea_price)


class CoffeeWindow(Screen):

    clickCounter = {}

    total_counter = 0
    daily_counter = 0

    def count(self, name, price):

        self.clickCounter.setdefault(name, [0, price])
        self.clickCounter[name][0] += 1
        self.daily_counter += self.clickCounter[name][1]
        self.total_counter += self.clickCounter[name][1]


class TeaWindow(Screen):

    clickCounter = {}

    total_counter = 0
    daily_counter = 0

    def count(self, name, price):

        self.clickCounter.setdefault(name, [0, price])
        self.clickCounter[name][0] += 1
        self.daily_counter += self.clickCounter[name][1]
        self.total_counter += self.clickCounter[name][1]


class MainWindow(Screen):
    pass


class WindowManager(ScreenManager):
    pass


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


class MainApp(App):

    def build(self):
        return kv


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

我的.kv：

<ItemButton@Button>:
    size_hint: 0.5, 0.12
    bold: True


WindowManager:
    MainWindow:
        id: main
    CoffeeWindow:
        id: coffee
    TeaWindow:
        id: tea
    DailyWindow:
        id: daily
    TotalWindow:
        id: total


<TotalWindow>:
    name: "total"

    BoxLayout:
        orientation: "vertical"
        pos_hint: {'x' : 0, 'center_y' : 0.57}
        size_hint: 1, 0.88

        Label:
            id: label1

    Button:
        size_hint: 0.5, 0.1
        pos_hint: {'right' : 0.5, 'y' : 0}
        text: "Go to Main"
        on_release:
            app.root.current = "main_window"
            app.root.transition.direction = "right"

    Button:
        size_hint: 0.5, 0.1
        pos_hint: {'right' : 1, 'y' : 0}
        text: "Delete"
        on_release:
            root.delete_total()


<MainWindow>:
    name: "main_window"

    BoxLayout:

        ItemButton:
            text: "Go to Coffee"
            pos_hint: {'x' : 0, 'center_y' : 0.5}
            on_release:
                app.root.current = "coffee"
                app.root.transition.direction = "left"

        ItemButton:
            text: "Go to Tea"
            pos_hint: {'x' : 0, 'center_y' : 0.5}
            on_release:
                app.root.current = "tea"
                app.root.transition.direction = "left"


<CoffeeWindow>:
    name: "coffee"

    GridLayout:
        rows: 3
        size_hint: 1, 0.8
        pos_hint: {'center_x' : 0.5, 'top' : 0.95}

        ItemButton:
            text: "black coffee"
            on_release:
                root.count("black coffee", 20)

        ItemButton:
            text: "milk coffee"
            on_release:
                root.count("milk coffee", 20)

        Button:
            size_hint: 0.5, 0.1
            text: "Show Daily Menu"
            on_release:
                app.root.current = "daily"
                app.root.transition.direction = "left"

        Button:
            size_hint: 0.5, 0.1
            text: "Show Total Menu"
            on_release:
                app.root.current = "total"
                app.root.transition.direction = "left"

        Button:
            size_hint: 0.5, 0.1
            text: "Go to Main"
            on_release:
                app.root.current = "main_window"
                app.root.transition.direction = "right"


<TeaWindow>:
    name: "tea"

    GridLayout:
        rows: 3
        size_hint: 1, 0.8
        pos_hint: {'center_x' : 0.5, 'top' : 0.95}

        ItemButton:
            text: "green tea"
            on_release:
                root.count("green tea", 20)

        ItemButton:
            text: "black tea"
            on_release:
                root.count("black tea", 20)

        Button:
            size_hint: 0.5, 0.1
            text: "Show Daily Menu"
            on_release:
                app.root.current = "daily"
                app.root.transition.direction = "left"

        Button:
            size_hint: 0.5, 0.1
            text: "Show Total Menu"
            on_release:
                app.root.current = "total"
                app.root.transition.direction = "left"

        Button:
            size_hint: 0.5, 0.1
            text: "Go to Main"
            on_release:
                app.root.current = "main_window"
                app.root.transition.direction = "right"


<DailyWindow>:
    name: "daily"

    BoxLayout:
        orientation: "vertical"
        pos_hint: {'x' : 0, 'center_y' : 0.57}
        size_hint: 1, 0.88

        Label:
            id: label1

        Label:
            id: label2

        Label:
            id: label3

    Button:
        size_hint: 0.5, 0.1
        text: "Go to Main"
        on_release:
            app.root.current = "main_window"
            app.root.transition.direction = "right"