python - 如何在 tkinter 中单击按钮后更新 Canvas 上的文本

Question

我想建立一个“商店”，一旦你点击某个按钮，它就会减去为此花费的金币。我面临的问题是单击按钮后刷新 Canvas ，以便显示您拥有多少金币。

class Hi:
    gold=100
    def showShop(self):
        def buyArcher():
            Hi.gold = int(Hi.gold) - 10
            updateScreen(canva)

        def updateScreen(name: Canvas):
            self.name = name
            self.name.update_idletasks()

        canva = Canvas(root, width="750", height="750",bg="brown")
        button1 =Button(root,text="Hello", command=buyArcher)
        button1.configure(width=10, activebackground="#33B5E5", relief=FLAT)
        button1_window = canva.create_window(10, 10, anchor=NW, window=button1)
        label = Label(text=Hi.gold, width=10)
        label.configure(width=10, activebackground="brown", relief=FLAT)
        label_window = canva.create_window(700, 10, anchor=NW, window=label)
        canva.pack()
        root.mainloop()

我希望点击按钮后屏幕上的金币会从 100 变为 90

Answer 1

这是一个小骨架，您可以扩展它来构建您的游戏。

它有一个类Player、一个类Shop和一个类Item；它为玩家保持金币余额，并在储蓄不足时拒绝消费。它为玩家和商店保留了基本的元素库存；商店不能出售自己没有的商品。

您可以通过点击 Canvas 上相应的元素来购买元素，并显示剩余的金币数量。

import tkinter as tk

class Player:
    def __init__(self, name, gold=100):
        self.name = name
        self.gold = 100
        self.items = []
    def pay_gold(self, amount):
        if self.gold >= amount:
            self.gold -= amount
            goldvar.set(self.gold)
            return True
        return False

    def __str__(self):
        return f'Player: {self.name} posessions: \n\t' + '\n\t'.join(f'{item.name}' for item in self.items) + f'\n\tgold: {self.gold}'


class Item:
    def __init__(self, name, price):
        self.name = name
        self.price = price
    def __eq__(self, other):
        return self.name == other.name


class Shop:
    def __init__(self, items):
        self.items = items[:]
    def buy_item(self, item):
        if item in self.items and player.gold >= item.price:
            if player.pay_gold(item.price):
                self.items.remove(item)
                player.items.append(item)
    def __str__(self):
        return 'shop inventory:\n\t' + '\n\t'.join(f'{item.name} at {item.price}' for item in self.items)


archer = Item('Archer', 10)
sword = Item('Sword', 15)
shop = Shop([archer, sword, archer, sword, archer, sword, archer, sword, archer, sword, archer, sword])
player = Player('Henryk')

print(shop)
print(player)

print()
shop.buy_item(archer)

print(player)
print(shop)

root = tk.Tk()
canvas = tk.Canvas(root, width="750", height="750", bg="brown")
button_sword = tk.Button(root, text="sword", command=lambda item=sword: shop.buy_item(item))
button1_window = canvas.create_window(10, 10, anchor=tk.NW, window=button_sword)
button_archer = tk.Button(root, text="archer", command=lambda item=archer: shop.buy_item(item))
button2_window = canvas.create_window(10, 30, anchor=tk.NW, window=button_archer)


goldvar = tk.IntVar()
goldvar.set(player.gold)
label = tk.Label(root, width=10)
label.configure(width=10, relief=tk.FLAT, textvariable=goldvar)
label_window = canvas.create_window(600, 10, anchor=tk.NW, window=label)
canvas.pack()
root.mainloop()