我如何使Tkinter入門小部件數據可用於其他功能

Question

我花了很多時間試圖用此代碼中的簡單入門小部件替換askinteger和askstring小部件。我相信有一種簡單的方法可以將來自入口小部件的信息傳遞給代碼中的其他函數，但我所研究和嘗試的所有內容都失敗了。任何幫助將是非常受歡迎的。

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 

這是我試過的那種東西。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() 

謝謝您的建議。我現在嘗試了以下方法，但仍然無法使print（fred）函數正常工作。我確信這是一個愚蠢的錯誤，但我不明白我做錯了什麼。

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

您必須在外部範圍中定義變量fred才能檢索它。 （還有其他的方式，但是這是你的代碼是如何構建的）：

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將包含來自entry字段檢索到的值，並作進一步處理