我正在使用Python中的tkinter模块创建一个GUI应用程序（主要是为了提高我的Python技能，我们在GCSE计算机科学中使用它），但是我遇到了一个令人烦恼的问题，我无法弄清楚。
我有一个UI，它包含多个标签和使用网格方法放置的输入框（可能无关紧要，但仍然如此）。还有4个单选按钮。单击UI上的按钮（在本例中为“下一步”按钮）时，相关输入框中的值将存储在字典中，然后将其附加到类中的列表中。
当我将值存储到字典中时，我的问题出现了 - 我从附加到radiobuttons的StringVar()得到的值总是空的 - 一个空字符串，它会出现。
有问题的课程如下。我正在调用get()函数中的next(self)方法。
为什么会发生这种情况，我该如何解决？
CreateQuizApp.py：
from tkinter import *
from tkinter import messagebox
from tkinter import filedialog
from TriviaTools import TriviaTools
class CreateQuizApp(Frame):
def __init__(self, parent):
Frame.__init__(self, parent)
self.parent = parent
self.parent.deiconify()
self.parent.geometry("600x300")
self.parent.title("New Quiz")
self.title=""
self.questions=[]
self.initUI()
def initUI(self):
if self.title is "":
titleLabel = Label(self.parent, text="Enter Quiz Title:")
titleLabel.grid(row=0, column=0, sticky=W+E)
titleEntry = Entry(self.parent)
titleEntry.grid(row=0, column=1, sticky=W+E)
nextButton = Button(self.parent, text="Next", command=self.next)
nextButton.grid(columnspan=2, sticky=W+E)
self.questionLabel = Label(self.parent, text="Enter Question:")
self.questionEntry = Entry(self.parent)
self.parent.grid_rowconfigure(0, weight=1)
self.parent.grid_columnconfigure(0, weight=1)
self.parent.grid_columnconfigure(1, weight=1)
self.answer1Label = Label(self.parent, text="Enter Answer 1:")
self.answer2Label = Label(self.parent, text="Enter Answer 2:")
self.answer3Label = Label(self.parent, text="Enter Answer 3:")
self.answer4Label = Label(self.parent, text="Enter Answer 4:")
self.answer1Entry = Entry(self.parent)
self.answer2Entry = Entry(self.parent)
self.answer3Entry = Entry(self.parent)
self.answer4Entry = Entry(self.parent)
self.categoryLabel = Label(self.parent, text="Category:")
self.categoryEntry = Entry(self.parent)
self.correctAnswer = StringVar()
self.correctAnswerLabel = Label(self.parent, text="Correct Answer:")
self.correctAnswer1 = Radiobutton(self.parent, text="1", variable=self.correctAnswer, value="1", anchor=CENTER)
self.correctAnswer2 = Radiobutton(self.parent, text="2", variable=self.correctAnswer, value="2", anchor=CENTER)
self.correctAnswer3 = Radiobutton(self.parent, text="3", variable=self.correctAnswer, value="3", anchor=CENTER)
self.correctAnswer4 = Radiobutton(self.parent, text="4", variable=self.correctAnswer, value="4", anchor=CENTER)
self.correctAnswer1.select()
self.correctAnswer2.deselect()
self.correctAnswer3.deselect()
self.correctAnswer4.deselect()
self.pointsLabel = Label(self.parent, text="Points:")
self.penaltyLabel = Label(self.parent, text="Penalty:")
self.pointsEntry = Entry(self.parent)
self.penaltyEntry = Entry(self.parent)
self.explanationLabel = Label(self.parent, text="Explanation:")
self.explanationEntry = Entry(self.parent)
#self.correctAnswer.set(1)
self.titleLabel = titleLabel
self.titleEntry = titleEntry
self.nextButton = nextButton
else:
try:
self.titleEntry.destroy()
self.titleLabel.destroy()
except:
pass
self.nextButton.grid_forget()
self.categoryLabel.grid(row=0, column=0, sticky=W+E)
self.categoryEntry.grid(row=0, column=1, columnspan=4, sticky=W+E)
self.questionLabel.grid(row=2, column=0, sticky=W+E)
self.questionEntry.grid(row=2, column=1, columnspan=4, sticky=W+E)
self.answer1Label.grid(row=4, column=0, sticky=W+E)
self.answer2Label.grid(row=5, column=0, sticky=W+E)
self.answer3Label.grid(row=6, column=0, sticky=W+E)
self.answer4Label.grid(row=7, column=0, sticky=W+E)
self.answer1Entry.grid(row=4, column=1, columnspan=4, sticky=W+E)
self.answer2Entry.grid(row=5, column=1, columnspan=4, sticky=W+E)
self.answer3Entry.grid(row=6, column=1, columnspan=4, sticky=W+E)
self.answer4Entry.grid(row=7, column=1, columnspan=4, sticky=W+E)
self.correctAnswerLabel.grid(row=9, column=0, sticky=W+E)
self.correctAnswer1.grid(row=9, column=1, sticky=W+E)
self.correctAnswer2.grid(row=9, column=2, sticky=W+E)
self.correctAnswer3.grid(row=9, column=3, sticky=W+E)
self.correctAnswer4.grid(row=9, column=4, sticky=W+E)
self.pointsLabel.grid(row=11, column=0, sticky=W+E)
self.pointsEntry.grid(row=11, column=1, columnspan=4, sticky=W+E)
self.penaltyLabel.grid(row=12, column=0, sticky=W+E)
self.penaltyEntry.grid(row=12, column=1, columnspan=4, sticky=W+E)
self.explanationLabel.grid(row=14, column=0, sticky=W+E)
self.explanationEntry.grid(row=14, column=1, columnspan=4, sticky=W+E)
self.nextButton.grid(row=17, column=0, columnspan=3, sticky=W+E)
self.finishedButton = Button(self.parent, text="Finished", command=self.finish)
self.finishedButton.grid(row=17, column=3, columnspan=2, sticky=E+W)
self.parent.grid_rowconfigure(0, weight=1)
self.parent.grid_rowconfigure(1, weight=1)
self.parent.grid_rowconfigure(2, weight=1)
self.parent.grid_rowconfigure(3, weight=1)
self.parent.grid_rowconfigure(4, weight=1)
self.parent.grid_rowconfigure(5, weight=1)
self.parent.grid_rowconfigure(6, weight=1)
self.parent.grid_rowconfigure(7, weight=1)
self.parent.grid_rowconfigure(8, weight=1)
self.parent.grid_rowconfigure(9, weight=1)
self.parent.grid_rowconfigure(10, weight=1)
self.parent.grid_rowconfigure(11, weight=1)
self.parent.grid_columnconfigure(0, weight=1)
self.parent.grid_columnconfigure(1, weight=1)
self.parent.grid_columnconfigure(2, weight=1)
self.parent.grid_columnconfigure(3, weight=1)
self.parent.grid_columnconfigure(4, weight=1)
def next(self):
if self.title is "":
widget = self.titleEntry
title = widget.get()
if title is "":
return
self.title = title
self.parent.title(self.title)
self.initUI()
else:
question = self.questionEntry.get()
category = self.categoryEntry.get()
points = self.pointsEntry.get()
penalty = self.penaltyEntry.get()
explanation = self.explanationEntry.get()
answers = [self.answer1Entry.get(), self.answer2Entry.get(), self.answer3Entry.get(), self.answer4Entry.get()]
if question is "" or category is "" or points is "" or penalty is "" or explanation is "":
messagebox.showerror("Please fill in all fields!", "All fields must be filled in.")
return
for value in answers:
if value is "":
messagebox.showerror("Please fill in all fields!", "All fields must be filled in.")
return
question = {"category":category, "question":question, "answers":answers, "correct":self.correctAnswer.get(), "points":points, "penalty":penalty, "explanation":explanation}
self.questions.append(question)
self.categoryEntry.delete(0, END)
self.questionEntry.delete(0, END)
self.answer1Entry.delete(0, END)
self.answer2Entry.delete(0, END)
self.answer3Entry.delete(0, END)
self.answer4Entry.delete(0, END)
self.pointsEntry.delete(0, END)
self.penaltyEntry.delete(0, END)
self.explanationEntry.delete(0, END)
def finish(self):
tools = TriviaTools()
file = tools.open_file(self.title+".trv", "w")
lines = []
lines.append(self.title+"\n")
for question in self.questions:
lines.append(question["category"]+"\n")
lines.append(question["question"]+"\n")
for answer in question["answers"]:
lines.append(answer+"\n")
lines.append(question["correct"]+"\n")
lines.append(str(question["points"])+"\n")
lines.append(str(question["penalty"])+"\n")
lines.append(question["explanation"]+"\n")
file.writelines(lines)
file.close()
self.parent.destroy()