Images on Dynamically Generated Buttons Glitch

[MRAB]

On 2019-07-07 19:28, Abdur-Rahmaan Janhangeer wrote:
> Greetings, i have this snippet:
> ---
> import json
> import os
> from tkinter import *
> from tkinter.ttk import *
> 
> root = Tk()
> jload = json.load
> buttons = list()
> programs = os.listdir('programs')
> for i, program in enumerate(programs):
>      jsonpath = 'programs/{}/cmdlaunch.json'.format(program)
>      info = jload(open(jsonpath))
>      photo = PhotoImage(file = 'icons/'+info['icon'])
>      photoimage = photo.subsample(3, 3)
>      buttons.append(Button(root, text = 'Click Me !', image = photoimage,
>                          compound = LEFT))
>      buttons[-1].pack()
> 
> root.mainloop()
> ---
> 
> All buttons are appearing but only the last button is displaying the image,
> any idea?
> 
You need to keep a reference to the image that you passed when creating 
the button; tkinter itself doesn't keep a reference to it:

import json
import os
from tkinter import *
from tkinter.ttk import *

root = Tk()
jload = json.load
buttons = list()
images = []
programs = os.listdir('programs')

for i, program in enumerate(programs):
      jsonpath = 'programs/{}/cmdlaunch.json'.format(program)
      info = jload(open(jsonpath))
      photo = PhotoImage(file = 'icons/'+info['icon'])
      photoimage = photo.subsample(3, 3)
      buttons.append(Button(root, text = 'Click Me !', image = photoimage,
                          compound = LEFT))
      buttons[-1].pack()
      images.append(photoimage)

root.mainloop()

In your code, 'photoimage' still refers to the last image, but there are 
no references to the previous images, so they're discarded.

(Why is tkinter like that? Who knows! :-))