如何在 tkinter 中保存按钮命令的结果？

Question

import tkinter as tk
from tkinter import simpledialog

def get_pass():

    user_password = simpledialog.askstring("Password Entry", "Enter your password here:")
    return user_password

submitButton = tk.Button(content, text="Start", command=get_pass)

#now I want to work with the password that the user entered.

用户应该点击“开始”按钮。单击按钮后，会出现一个 tkinter 消息框，要求用户输入密码。用户输入他们的密码并提交。根据上面的代码，密码返回一个名为 user_password 的字符串。

问题是，我如何使用用户输入的内容？按钮不保存函数的返回值。

Answer 1

command= 无法接收从get_pass() 返回的值，因此您可以使用global 变量（或StringVar）来分配user_password。或者直接在get_pass()中使用这个值来检查密码，你就不用回了。

import tkinter as tk
from tkinter import simpledialog

def get_pass():
    # inform function to use external/global variable when you use `=`
    global user_password

    # `user_password_var` is global variable too
    # but it doesn't need `global user_password_var` 
    # because it doesn't need `=` to assign value.

    result = simpledialog.askstring("Password Entry", "Enter your password here:")

    user_password = result
    # or
    user_password_var.set(result)
    # or
    if result != '123456':
        label['text'] = "ERROR: password is incorrect"
    else:
        label['text'] = "password is OK"

# --- main ---

root = tk.Tk()

# it creates global variable 
user_password = ''
# or
user_password_var = tk.StringVar()

label = tk.Label(root)
label.pack()

submitButton = tk.Button(root, text="Start", command=get_pass)
submitButton.pack()

# both variables are empty before `mainloop`

root.mainloop()

# both variables have value after `mainloop`

# print after you exit program
print(user_password)
print(user_password_var.get())

Answer 2

首先您需要添加submitButton.pack() 或submitButton.grid() 以在tk 窗口中显示按钮。返回 user_password 不起作用，因为您没有将“命令”分配给密码。你可以把你的函数改成这样：

import tkinter as tk
from tkinter import simpledialog

def get_pass():
    global user_password
    user_password = simpledialog.askstring("Password Entry", "Enter your password here:")
    content.destroy()

content=tk.Tk()
submitButton = tk.Button(content, text="Start", command=get_pass)
submitButton.config(height=6, width=25, fg='red') #looks a little nicer
submitButton.pack()
content.mainloop()

#Do stuff with user_password
#print(user_password)

当您稍后打印 user_password 时，它将显示通过 simpledialog 输入的密码。密码现在是 user_password。