python3中的Tkinter，菜单栏不起作用

Question

Well, i want to add menubar, but something is going wrong.

It says: AttributeError: 'NoneType' object has no attribute 'config'

My code:

from tkinter import *


class ApplicationWindow(Tk):

    def __init__(self, master=None):
        Tk.__init__(self, master)
        self.master = master
        self.geometry('800x400')
        self.f_app = Frame(self).pack()
        menubar = Menu(self.master)
        self.master.config(menu=menubar)

        fileMenu = Menu(menubar)
        fileMenu.add_command(label="Exit", command=self.onExit)
        menubar.add_cascade(label="File", menu=fileMenu)
        self.b_log = Button(self, width=10, text="Войти", command=self.func).pack()


    def onExit(self):
        self.quit()

    def func(self):
        print("hello")

def main():
    # root = tk
    app = ApplicationWindow() 
    app.mainloop()


if __name__ == '__main__':
    main()

Answer 1

You're initializing your ApplicationWindow class without passing any arguments in, like this app = ApplicationWindow() . In your init method, you give master a None default, and when you try to use master.config it says

'NoneType' object has no attribute 'config'

Try passing an argument in when you initialize the instance of ApplicationWindow . Whatever it is that you want master to be (just not a None object).

I have updated your code (below) and it runs. The button works, and the exit function closes the window. There was a lot to fix, but it runs without error. Take it from here:

import tkinter


class ApplicationWindow(tkinter.Tk):

    def __init__(self, master=None):
        # Tk.__init__(self, master)
        self.master = master
        self.master.geometry('800x400')
        self.master.f_app = tkinter.Frame(self.master).pack()
        menubar = tkinter.Menu(self.master)
        self.master.config(menu=menubar)

        fileMenu = tkinter.Menu(menubar)
        fileMenu.add_command(label="Exit", command=self.onExit)
        menubar.add_cascade(label="File", menu=fileMenu)
        self.b_log = tkinter.Button(self.master, width=10, text="Войти", command=self.func).pack()


    def onExit(self):
        self.master.destroy()

    def func(self):
        print("hello")

def main():
    root = tkinter.Tk()
    app = ApplicationWindow(root) 
    root.mainloop()


if __name__ == '__main__':
    main()

Answer 2

You have an argument named master=None defaults to None. So when you create an instance of ApplicationWindow() without parameter your master argument gets None, and here you are calling config() method but your master is none and it doesnt have a method named config.

class ApplicationWindow(Tk):
    def __init__(self, master=None):
        ...
        self.master.config(menu=menubar) # Error accurred here

def main():
    # root = tk
    app = ApplicationWindow() # pass an argument