Image loading problem

[Peter Otten]

sweating_ant at yahoo.com wrote:

> I am working on an image project, and I can display my image in main(). I 
mean, I can load my image in my main(). Needless, it is awkward. I am trying 
to load my image with a function, but got an empty image window popped up, 
no image content loaded. Please take a look at code:
> 
> 
> 
> rom Tkinter import *
> 
> def load_img(win):      
>         img = PhotoImage(file="xxx.gif")
>         Label(win, image=img).pack()
>         
> win = Tk()
> load_img(win)
> win.mainloop()
> 
> Somebody can help me out? Thanks!

It's not your fault, there's an odd quirk in the library: you have to keep a 
reference of the PhotoImage instance around to prevent the image from being 
garbage-collected. For example

from Tkinter import *

def load_img(win):
    global img

    img = PhotoImage(file="xxx.gif")
    Label(win, image=img).pack()

win = Tk()
load_img(win)
win.mainloop()

will work because img is now a global that is not deleted until the script 
ends (but don't run the function twice -- then the first image will 
disappear).