使用for循环创建和获取tkinter复选框中的值

Question

这段代码是我项目的一部分，我必须管理50名(或更多(学生的出勤率。

我想要的是，所有复选框最初都应该被"选中">(显示当前状态(，当我取消选中随机复选框(标记缺席(并单击Submit按钮

时(尚未在窗口底部创建(例如：['01/08/2020', '2018-MC-7', '2018-MC-11', '2018-MC-23', '2018-MC-44']

事实上，我的计划是，当我得到一个列表时，我会很容易地将其写入文本文件。此外，如果有另一种方法可以创建多个可滚动复选框，而不将其打包在画布中，那么请告诉我！

from tkinter import *
from tkcalendar import DateEntry
root = Tk()
root.geometry('920x600+270+50')
root.minsize(920,600)
Attendance_frame = Frame(root)    ### Consider it a Main Frame
Attendance_frame.pack()
attendaceBox = LabelFrame(Attendance_frame, text = 'Take Attendance', bd = 4, relief = GROOVE, labelanchor = 'n',font = 'Arial 10 bold', fg = 'navy blue', width = 850, height = 525)     # A Label Frame inside the main frame
attendaceBox.pack_propagate(0)
attendaceBox.pack(pady = 15)
dateFrame = Frame(attendaceBox)    # A small frame to accommodate date entry label & entry box
dateFrame.pack(anchor = 'w')
font = 'TkDefaultFont 10 bold'
date_label = Label(dateFrame, text = 'Enter Date : ', font = font).grid(row = 0, column =  0, sticky = 'w', padx = 10, pady = 10)
date_entry = DateEntry(dateFrame, date_pattern = 'dd/mm/yyyy', showweeknumbers = FALSE, showothermonthdays = FALSE)
date_entry.grid(row = 0, column = 1, sticky = 'w')
noteLabel = Label(attendaceBox, text = 'Note: Uncheck the boxes for absentees').pack(anchor = 'w', padx = 10, pady = 5)
canvas = Canvas(attendaceBox, borderwidth=0, background="#ffffff")
checkFrame = Frame(canvas, width = 100, height = 50)
vsb = Scrollbar(canvas, orient="vertical", command=canvas.yview)
canvas.configure(yscrollcommand=vsb.set)
vsb.pack(side="right", fill="y")
canvas.pack(side="left", fill="both", expand=True)
canvas.pack_propagate(0)
canvas.create_window((4,4), window=checkFrame, anchor="nw")
def onFrameConfigure(canvas):
'''Reset the scroll region to encompass the inner frame'''
canvas.configure(scrollregion=canvas.bbox("all"))
checkFrame.bind("<Configure>", lambda event, canvas=canvas: onFrameConfigure(canvas))
for i in range(0,51):     # A loop to create Labels of students roll numbers & names
c = Checkbutton(checkFrame, text = f"{'2018-MC-'+str(i+1)}       Student {i+1}")
c.grid(row = i, column = 0, padx = 10, sticky = 'w')

mainloop()

Answer 1

首先，每个Checkbutton都需要StringVar，以便稍后获得Checkbuttons的状态。然后，您可以使用列表来保存StringVars，以便以后可以访问它们。您可以将checkbuttons的onvalue设置为与其关联的卷号。

您也可以使用Text小部件，而不是Canvas+Frame。下面是一个例子：

import tkinter as tk
root = tk.Tk()
frame = tk.Frame(root)
frame.pack()
text = tk.Text(frame, width=40, height=20)
text.pack(side=tk.LEFT, fill=tk.BOTH)
vars = []
for i in range(51):
rollnum = '2018-MC-'+str(i+1)
var = tk.StringVar(value=rollnum)
cb = tk.Checkbutton(text, text=rollnum, variable=var, onvalue=rollnum, offvalue='', bg='white')
text.window_create('end', window=cb)
text.insert('end', 'n')
vars.append(var)
vsb = tk.Scrollbar(frame, orient=tk.VERTICAL, command=text.yview)
vsb.pack(side=tk.RIGHT, fill=tk.Y)
text.config(yscrollcommand=vsb.set)
def submit():
# extract roll numbers for checked checkbuttons
result = [var.get() for var in vars if var.get()]
print(result)
tk.Button(root, text='Submit', command=submit).pack()
root.mainloop()