在GUI (Tkinter) Python中从函数外部访问变量

import tkinter as tk

# 定义全局变量
global_var = 0

def update_var():
    global global_var
    global_var += 1

def display_var():
    global global_var
    print(global_var)

root = tk.Tk()

button1 = tk.Button(root, text="Update Variable", command=update_var)
button1.pack()

button2 = tk.Button(root, text="Display Variable", command=display_var)
button2.pack()

root.mainloop()

import tkinter as tk

class App:
    def __init__(self):
        self.var = 0

    def update_var(self):
        self.var += 1

    def display_var(self):
        print(self.var)

root = tk.Tk()

app = App()

button1 = tk.Button(root, text="Update Variable", command=app.update_var)
button1.pack()

button2 = tk.Button(root, text="Display Variable", command=app.display_var)
button2.pack()

root.mainloop()

import tkinter as tk

def create_counter():
    count = 0

    def counter():
        nonlocal count
        count += 1
        print(count)

    return counter

root = tk.Tk()

counter = create_counter()

button1 = tk.Button(root, text="Update Variable", command=counter)
button1.pack()

root.mainloop()