我如何使Tkinter入门小部件数据可用于其他功能

Question

我花了很多时间试图用此代码中的简单入门小部件替换askinteger和askstring小部件。我相信有一种简单的方法可以将来自入口小部件的信息传递给代码中的其他函数，但我所研究和尝试的所有内容都失败了。任何帮助将是非常受欢迎的。

from tkinter import * 
from tkinter.simpledialog import askinteger 
from tkinter.simpledialog import askstring 
from random import randrange 


def read_file(words_file): 
    with open(words_file, 'r') as f: # Read the text file 
     wordList = [] # Create an empty string called wordList 
     for line in f: # For every line in the text file 
      wordList += line.split() # Add another item to the list 
     f.close() 
     return wordList # Return the list 


def select_word(wordList, word): 
    wordLength = 0 

    length = askinteger("Letters", "How Many Letters?") # Ask user for  amount of letters 

    while wordLength != length: 
     wordNumber = randrange(0, len(wordList)) # Randomly select a number between 0 and length of wordList 
     word = wordList[wordNumber] # Select a word from the list using wordNumber 
     word = word.upper() 
     wordLength = len(word) # Calculate the length of the selected word 
    return word 

def get_letter(): 

    letter = askstring("Please enter a letter", "Which letter would you like to try?") 

    letter = letter.upper() # Convert letter to uppercase 
    return letter 

这是我试过的那种东西。我也使用了stringvar。

from tkinter import * 

master = Tk() 
e = Entry(master) 
e.pack() 
e.focus_set() 

def callback(): 
    print (e.get()) 
    global fred 
    fred = e.get() 
    print(fred) 
    return fred 

b = Button(master, text="get", width=10, command=callback) 
b.pack() 

print(fred) 

mainloop() 

谢谢您的建议。我现在尝试了以下方法，但仍然无法使print（fred）函数正常工作。我确信这是一个愚蠢的错误，但我不明白我做错了什么。

from tkinter import * 

master = Tk() 
e = Entry(master) 
e.pack() 
e.focus_set() 

fred = ''  # declare fred in the outer scope 

def callback(): 
    print (e.get()) 
    fred = (e.get()) 
    return fred # removed global statement as I understand they should be avoided 

b = Button(master, text="get", width=10, command=callback) 
b.pack() 

print(fred) 

mainloop() 

Answer 1

您必须在外部范围中定义变量fred才能检索它。 （还有其他的方式，但是这是你的代码是如何构建的）：

from tkinter import * 

master = Tk() 
e = Entry(master) 
e.pack() 
e.focus_set() 

fred = ''  # declare fred in the outer scope 

def callback(): 
    print (e.get()) 
    global fred 
    fred = e.get() 
    print(fred) 
    # return fred # as fred is global, returning it is optional 

b = Button(master, text="get", width=10, command=callback) 
b.pack() 

mainloop() 

fred将包含来自entry字段检索到的值，并作进一步处理