我继承的类 MenuBar(tk.Menu) 不显示 Menubar

Question

I have been trying to add a main menu to my program and am having trouble with it. I don't exactly understand the class structure of python3 as I'm fairly new to programming with it. I am running on ubuntu 18.04 and here is the code I am having trouble with.

#! /usr/bin/env python3

import tkinter as tk
from tkinter import *

class Application(tk.Tk):

    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)
        container = tk.Frame(self)

        menubar = MenuBar(self)
        self.config(menu=menubar)

    def quitButton(self):
        self.destroy()

class MenuBar(tk.Menu):
    def __init__(self, parent):
        tk.Menu.__init__(self, parent)
        self.controller = parent

        menubar = tk.Menu(self, tearoff=False)
        filemenu = tk.Menu(menubar, tearoff=0)
        filemenu.add_command(label="Test", command=self.test_Test)
        filemenu.add_separator()
        filemenu.add_command(label="Exit", command=lambda:    self.controller.quitButton())
        menubar.add_cascade(label="File", menu=filemenu)

    def test_Test(self):
        print("This is a test")

if __name__ == "__main__":
    app = Application()
    app.title("test") 
    app.mainloop()

The file menu does not appear for me. Any Help?

Answer 1

Question : tkinter ... not showing Main Menu

There are couple problems here.

 class MenuBar(tk.Menu): def __init__(self, parent): tk.Menu.__init__(self, parent) self.controller = parent

Here, you create a new tk.Menu(... with parent == self .
The Variable menubar hold the tk.Menu(... object.

 menubar = tk.Menu(self, tearoff=False)

A class __init__ methode returns itself, therefore you don't return the new menubar .
You return a class MenuBar(tk.Menu) object, which ist empty !

change to

class MenuBar(tk.Menu):
    def __init__(self, parent):

• Your class MenuBar is the new menubar! Therefore, the init parameters goes here

   tk.Menu.__init__(self, parent, tearoff=False)

• The submenus parent is this class, therefore pass self .

   filemenu = tk.Menu(self, tearoff=0)

• Add filemenu items as used

   filemenu.add_command(label="Test", command=self.test_Test) filemenu.add_separator() filemenu.add_command(label="Exit", command=lambda: self.controller.quitButton())

• Add the submenu to this object, therefore use self.add... .

   self.add_cascade(label="File", menu=filemenu)

---

You can .config(... within class MenuBar doing:

        parent.config(menu=self)

Tested with Python: 3.5 - TkVersion': 8.6