Tkinter List of Canvases

[MRAB]

On 2020-11-10 10:01, ChalaoAdda wrote:
> Hello,
> 
> I have a list of canvas of images. I would like to display all the images. But it displays the last image. Here is my code.
> 
> from tkinter import *
> from PIL import Image, ImageTk
> 
> root = Tk()
> 
> canvas_width = 265
> canvas_height = 130
> canvases = []
> 
> r, c = 0, 0
> 
> for tile in tiles:
>      img = tile.image
>      photo = ImageTk.PhotoImage(image=img)
>      can = Canvas(root, width=canvas_width, height=canvas_height)
>      can.create_image(0, 0, image=photo, anchor=NW)
>      canvases.append(can)
>      can.grid(row=r, column=c)
> 
>     c += 1
>      if c % 5 == 0:
>          r += 1
>          c = 0
> 
> 
> root.mainloop()
> 
You need to keep a reference to the images. In your code, 'photo' still 
refers to the last photoimage, so that's why it's displayed; there are 
no references to the others, so they're garbage-collected. (You probably 
expected that 'create_image' would keep a reference to the image, but it 
doesn't. tkinter has its idiosyncrasies!)

Try adding a list for the photoimages:

...
photos = []

for tile in tiles:
     img = tile.image
     photo = ImageTk.PhotoImage(image=img)
     photos.append(photo)
     can = Canvas(root, width=canvas_width, height=canvas_height)
...