选择后关闭 tkinter 菜单

Question

I Found this script on pythonspot tutorial, But I can't make it close after a selection has been made, I tried adding root.destroy() but it didn't do it. What I want is basically to store the selection in a variable (so I can use later on) and destroy the window after selection. I am very new to tkinter

from tkinter import *
root = Tk()
root.title("Tk dropdown example")

# Add a grid
mainframe = Frame(root)
mainframe.grid(column=0,row=0, sticky=(N,W,E,S) )
mainframe.columnconfigure(0, weight = 1)
mainframe.rowconfigure(0, weight = 1)
mainframe.pack(pady = 100, padx = 100)

# Create a Tkinter variable
tkvar = StringVar(root)

# Dictionary with options
choices = { 'Pizza','Lasagne','Fries','Fish','Potatoe'}
tkvar.set('Pizza') # set the default option

popupMenu = OptionMenu(mainframe, tkvar, *choices)
Label(mainframe, text="Choose a dish").grid(row = 1, column = 1)
popupMenu.grid(row = 2, column =1)

# on change dropdown value
def change_dropdown(*args):
    print( tkvar.get() )

# link function to change dropdown
tkvar.trace('w', change_dropdown)

root.mainloop()
#root.destroy()

Answer 1

You can use the command option of the OptionMenu to execute a function when the user selects an item (taking the chosen item in argument). In this function, you will close the window and assign the user choice to a global variable so that you can reuse it after closing GUI:

def on_selection(value):
    global choice
    choice = value
    root.destroy()

Here is a full example:

import tkinter as tk
root = tk.Tk()

# Create a Tkinter variable
tkvar = tk.StringVar(root)

# options
choices = ['Pizza','Lasagne','Fries','Fish','Potatoe']
tkvar.set('Pizza') # set the default option

def on_selection(value):
    global choice
    choice = value  # store the user's choice
    root.destroy()  # close window

popupMenu = tk.OptionMenu(root, tkvar, *choices, command=on_selection)
tk.Label(root, text="Choose a dish").grid(row=0, column=0)
popupMenu.grid(row=1, column =0)

root.mainloop()

# Do whatever you want with the user's choice after closing the window
print('You have chosen %s' % choice)