Tkinter OptionMenu已禁用但可以扩展

Question

Is there any solution of write-protecting a tkinter OptionMenu while retaining the possibility to inspect the available Options?

Background: I have a tkinter OptionMenu containing a selection of files that the user can "quick-load" into the application. However it might be that the user does not have permission to load new files.

I now indicate this by putting the OptionMenu in disabled state. But then the dropdown cannot be expanded anymore; meaning that the user cannot look at the available files.

Answer 1

You can disable each entry of the menu instead of disabling the optionmenu totally using menu.entryconfigure(<index>, state='disabled') . The menu of an optionmenu is stored in the 'menu' property:

import tkinter as tk
root = tk.Tk()
var = tk.StringVar(root)
opmenu = tk.OptionMenu(root, var, *['item %i' % i for i in range(5)])
opmenu.pack()
menu = opmenu['menu']
for i in range(menu.index('end') + 1):
    menu.entryconfigure(i, state='disabled')

So you can view all the items in the menu but they are not clickable.

Answer 2

Yes, it is possible to disable the menu and still be able to open it just to see the list. The menu used in OptionMenu is tkinter Menu() and you can access it.

Example:

Op = OptionMenu(root, var, 'First', 'Second', 'Third')
Op.pack()

# Op_Menu is the Menu() class used for OptionMenu
Op_Menu = Op['menu']

Then you can do anything with the Op menu same as Menu()

---

In your case , How to disable?

We can use menu.entryconfig(index, options) to configure state = 'disabled' / 'normal' as per the user.

Example:

import tkinter as tk

root = tk.Tk()
root.geometry('250x250+100+100')

str = tk.StringVar()
str.set('Select')

Op = tk.OptionMenu(root, str, "First", "Second", "Third")
Op.pack()


# This will disable the First and Third entries in the Op
# state = 'disable' / 'normal'
Op['menu'].entryconfig(0, state='disable')
Op['menu'].entryconfig("Third", state='disable')


entries = Op['menu'].index('end')     # This will get the total no. of entries.

# If you want to disable all of the entries uncomment below 2 lines.

# for i in range(entries+1):
#     Op['menu'].entryconfig(i, state='disable')


root.mainloop()

For better understanding on how the Menu() is defined inside OptionMenu class can check the source code of OptionMenu() class . (from line 3959 )