我遇到的问题是，在单击“Enter”按钮之前，在OptionMenu顶部显示所选值的第一遍中，下面的功能正常工作：
然而，在第二次传递并且任何将来传递给该函数时，在按下“Enter”按钮之前，所选值不会显示在OptionMenu的顶部（尽管如果选择它将被使用）：
代码是：
def load_create_list(self):
self.app = Toplevel(self.parent)
self.parent.withdraw()
self.app.title("Rgs2")
self.student = []
self.student1=[]
self.gs1=0
self.ng1=0
options = ["2", "3", "4", "5", "6", "7"]
self.results=[]
self.ngg=StringVar() #for the option menu widget the variable must be a stringVar not a normal string, int etc.
self.ng = Label(self.app, text="Number of groups")
self.ng.grid(row=2, column=0)
self.ngg.set("3")
self.ng1 = OptionMenu(self.app, self.ngg, *options)
self.ng1.grid(row=2, column=1, ipadx=10)
for i in range(0,len(self.x3)):
self.L1 = Label(self.app,text="Student")
self.L1.grid(row=i+4, column=0)
self.en = Entry(self.app)
self.en.insert(END, self.x3[i])
self.en.grid(row=i+4, column=1)
self.student.append(self.en)
self.el = int(len(self.student)+1)
for h in range(self.el,self.el+5):
self.L2 = Label(self.app,text="Student")
self.L2.grid(row=h+4, column=0)
self.em = Entry(self.app)
self.em.grid(row=h+4, column=1)
self.student.append(self.em)
button=Button(self.app,text="enter",command=lambda : self.hallo2()).grid(row=h+7,column=0)
button=Button(self.app,text="Save List",command=lambda : self.save_list2()).grid(row=h+7,column=1)
我已尝试过所有内容，但无法理解可能导致此问题的原因。任何帮助都将很高兴。看起来非常奇怪的行为可能是导致问题的功能之外的东西吗？
完整代码是：
from Tkinter import *
from tkFileDialog import askopenfile
class main_menu:
def __init__(self, parent):
self.myParent = parent
self.myContainer1 = Frame(parent)
parent.title("Random Group Sorter")
self.myContainer1.pack()
self.button1 = Button(self.myContainer1, command = lambda : self.hope())
self.button1.configure(text="Create List", height = 1, width = 20, font=("Arial", 16))
self.button1.pack(side=TOP)
self.button1.focus_force()
self.button3 = Button(self.myContainer1, command = lambda : self.hope1())
self.button3.configure(text="Load List", height = 1, width = 20, font=("Arial", 16))
self.button3.pack(side=TOP)
self.button2 = Button(self.myContainer1, command = lambda : exit(), )
self.button2.configure(text="Exit",height = 1, width = 20, font=("Arial", 16))
self.button2.pack(side=TOP)
def hope(self):
self.myParent.destroy()
create_list()
def hope1(self):
self.myParent.destroy()
load_list()
class create_list():
def __init__(self):
parent = Tk()
self.parent=parent
self.student = []
self.student1 =[]
self.student2 =[]
self.fake_student = []
self.results=[]
self.ngg = StringVar()# for the option menu widget the variable must be a stringVar not a normal string, int etc.
self.ng = Label(text="Number of groups")
self.ng.grid(row=2, column=0)
self.ng = OptionMenu(parent, self.ngg, "2", "3", "4", "5","6")
self.ng.grid(row=2, column=1)
for i in range(3,21):
self.L1 = Label(text="Student")
self.L1.grid(sticky=E)
self.en = Entry(parent)
self.en.grid(row=i, column=1)
self.student.append(self.en)
button=Button(parent,text="Enter",command=lambda : self.hallo()).grid(row=23,column=0)
button=Button(parent,text="Save List",command=lambda : self.save_list()).grid(row=23,column=1)
parent.mainloop()
def hallo(self):
self.gs1 = int(len(self.student))
self.ng1 = int(self.ngg.get())# still need to use .get even though a stringvar
for entry in self.student:
self.student1.append(entry.get())
self.student1 = filter(None, self.student1)
for i in self.student1:# this is added as there are duplicate entries in the student list if saved
if i not in self.student2:
self.student2.append(i)
self.parent.destroy()
lis_an(self.student2,self.ng1)
def save_list(self):
for entry in self.student:
self.student1.append(entry.get())
self.student1 = filter(None, self.student1)
import tkFileDialog
root = Tk()
root.withdraw()
file_name = tkFileDialog.asksaveasfile(parent=root)
root.destroy()
print >>file_name, "\n"
print >>file_name, "\n".join(self.student1)
file_name.close()
class load_list:
def __init__(self):
self.x = []
self.x3 = []
self.load_clean()
self.root = Tk()
def load_clean(self):#option to load an already created file, cleans unwanted info from the list
import tkFileDialog
root = Tk()
root.withdraw()
file_name = tkFileDialog.askopenfile(parent=root)
root.destroy()
self.x = file_name.readlines()
file_name.close()
x2 =self.x[:]
for z in self.x:
if z [0:6]== "Random" or z == '\n' or z[0:5] == "Group":
x2.remove(z)
for c in range (0,len(x2)):
v = x2[c].rstrip()# this strip spaces and \n from each list item and returns the cleaned up string
self.x3.append(v)
self.load_create_list()
def load_create_list(self):
parent = Tk()
self.parent=parent
self.student = []
self.student1=[]
self.gs1=0
self.ng1=0
self.results=[]
self.ngg = StringVar()# for the option menu widget the variable must be a stringVar not a normal string, int etc.
self.ng = Label(text="Number of groups")
self.ng.grid(row=2, column=0)
self.ng = OptionMenu(parent, self.ngg, "2", "3", "4", "5", "6")
self.ng.grid(row=2, column=1)
for i in range(0,len(self.x3)):
self.L1 = Label(text="Student")
self.L1.grid(row=i+3, column=0)
self.en = Entry(parent)
self.en.insert(END, self.x3[i])
self.en.grid(row=i+3, column=1)
self.student.append(self.en)
self.el = int(len(self.student)+1)
for h in range(self.el,self.el+5):
self.L2 = Label(text="Student")
self.L2.grid(row=h+3, column=0)
self.em = Entry(parent)
self.em.grid(row=h+3, column=1)
self.student.append(self.em)
button=Button(parent,text="enter",command=lambda : self.hallo2()).grid(row=h+6,column=0)
button=Button(parent,text="Save List",command=lambda : self.save_list2()).grid(row=h+6,column=1)
parent.mainloop()
def hallo2(self):
self.student2= []
self.gs1 = int(len(self.student))
self.ng1 = int(self.ngg.get())# still need to use .get even though a stringvar
for entry in self.student:
self.student1.append(entry.get())
self.student1 = filter(None, self.student1)
for i in self.student1:# this is added as there are duplicate entries in the student list if saved
if i not in self.student2:
self.student2.append(i)
self.parent.destroy()
lis_an(self.student2,self.ng1)
def save_list2(self):
for entry in self.student:
self.student1.append(entry.get())
self.student1 = filter(None, self.student1)
import tkFileDialog
root = Tk()
root.withdraw()
file_name = tkFileDialog.asksaveasfile(parent=root)
root.destroy()
print >>file_name, "\n"
print >>file_name, "\n".join(self.student1)
file_name.close()
class lis_an:
def __init__(self,student1,ng1):
self.student1 = student1
self.ng1=ng1
self.results = []
self.randomList()
def randomList(self): # this creates a random list of students on the course
import random
studentb = self.student1[:]# this is added as otherwise the student list is overwritten
studentc = []
for i in range(len(studentb)):
element = random.choice(studentb)
studentb.remove(element)
studentc.append(element)
self.student1 = studentc
self.partition()
def partition(self): # this creates sub list of the student list containing the groups of students
increment = len(self.student1) / float(self.ng1)
last = 0
i = 1
while last < len(self.student1):
idx = int(round(increment * i))
self.results.append(self.student1[last:idx])
last = idx
i += 1
output(self.results, self.ng1)
class output:
def __init__(self, student, ng1):
self.ng1 = ng1
self.student = student
self.parent = Tk()
for item1 in range (0,len(self.student)):
test1 = "Group " + str(item1+1)+ ":"
v = Label(self.parent, text=test1, font=("Arial", 13))
test = "\n".join(self.student[item1])
w = Label(self.parent, text=test, justify = LEFT, font=("Arial", 12))
v.pack(side="top", anchor="w")
w.pack(side="top", anchor="w")
button=Button(self.parent,text="Repeat",command=lambda : self.join_list()).pack(side="top", anchor="w")
button=Button(self.parent,text="Main Menu",command=lambda : self.menu_link()).pack(side="top", anchor="w")
mainloop()
def join_list(self):#this function creates a new undivided version of student to feed back to lis_an
self.parent.destroy()
self.student = [j for i in self.student for j in i]
lis_an(self.student,self.ng1)
def menu_link(self):#destroys the parent frame and returns back to main menu
self.parent.destroy()
main()
def main():
parent = Tk()
myapp = main_menu(parent)
parent.mainloop()
main()
这个问题非常简单的解决方案。我没有在父窗口小部件中将self.ngg定义为StringVar，所以：
self.ngg = StringVar()
会导致错误，
self.ngg = StringVar(self.app)
解决问题。不太确定为什么会在第二次和后续使用函数时发生这种情况，而不是第一次使用。