刷新标签 Tkinter？

Question

I want to refresh the the password Label every time the refresh button is pressed. I tried the .config but it doesn't work.

import random
import string
import tkinter.messagebox
from tkinter import *

def get_all_passwords():
    with open('Passwords.txt') as f:
        global password_Text
        password_Text = f.read()
        f.close()

def main_window():
    def all_passwords_text():
        global password_Text
        All_passwords_label.config(text=password_Text)
    All_passwords_label = tkinter.Label(
        window,
        text=password_Text,
        foreground="black",
        background="white",
        width=25,

    )
    password_label = tkinter.Label(
        text=password,
        foreground="white",
        background="black",
        width=20,
    )
   
    save_button = tk.Button(
        text='save',
        width=10,
        cursor='hand1',
        bg='light gray',
        command=lambda:[write_password_to_txt(), All_passwords_label, window.update()]
    )
    refresh_button = tk.Button(
        text='Refresh',
        width=20,
        bg="white",
        fg="black",
        command=all_passwords_text
    )

    All_passwords_label.pack(side='right')
    password_label.pack()
    safe_entry.pack()
    save_button.pack()
    refresh_button.pack()
    window.mainloop()


random_password()
main_window()

Answer 1

import tkinter as tk  # avoid star imports; this can lead to namespace pollution
import tkinter.messagebox
# other imports, etc.

# declare a StringVar to store the label text
password_var = tk.StringVar()


def get_all_passwords():
    with open('Passwords.txt') as f:
        password_Text = f.read()
        password_var.set(password_text)  # update 'password_var'
        # f.close() - you don't need this when using 'with'
        # see link below

"Context Managers and Python's with Statement"

# add a 'textvariable' binding to your label
# the label text will update whenever the variable is set
All_passwords_label = tk.Label(
    window,
    text=password_Text,
    textvariable=password_var  # add this!
    foreground="black",
    background="white",
    width=25,
)

Now any time you call get_all_passwords() the label text of All_passwords_label should update. Note that you no longer need the all_passwords_text function at all, and you don't need to use globals either.