How to refresh the window to show a new image in pysimlegui

Question

When I click the button to change the image, the window refresh does not work. I don't know how to implement it properly. How can I refresh the api with the button. I'm new to pysimplegui; can somebody point me in the correct direction?

from io import BytesIO
import PySimpleGUI as sg
from PIL import Image
import requests, json

def image_to_data(im):
    with BytesIO() as output:
        im.save(output, format="PNG")
        data = output.getvalue()
    return data

cutURL = 'https://meme-api.herokuapp.com/gimme/wholesomememes'
imageURL = json.loads(requests.get(cutURL).content)["url"]
data = requests.get(imageURL).content
stream = BytesIO(data)
img = Image.open(stream)
giy=image_to_data(img)
control_col = sg.Column([
    [sg.Button('next meme', key = '_3_')],])
image_col = sg.Column([[sg.Image(giy, key = '-IMAGE-')]])
layout = [[control_col,image_col]]
window = sg.Window('meme', layout,finalize=True)









while True:
    event, values = window.read()
    
    if event is None:
        break
    if '_3_' in event:
       
       window.refresh()
       
    
window.close()

Answer 1

Method window.refresh() called to update the GUI if you do some changes to element(s) and you want to update it immediately before the script execute next window.read() which also update the GUI.

It is necessary to download next picture from website again by your code, window.refresh() won't automatically update new image.

from io import BytesIO
import PySimpleGUI as sg
from PIL import Image
import requests, json

def image_to_data(im):
    with BytesIO() as output:
        im.save(output, format="PNG")
        data = output.getvalue()
    return data

def get_data():
    cutURL = 'https://meme-api.herokuapp.com/gimme/wholesomememes'
    imageURL = json.loads(requests.get(cutURL).content)["url"]
    data = requests.get(imageURL).content
    stream = BytesIO(data)
    img = Image.open(stream)
    giy = image_to_data(img)
    return giy

control_col = sg.Column([[sg.Button('next meme', key = '_3_')],])
image_col = sg.Column([[sg.Image(get_data(), key = '-IMAGE-')]])
layout = [[control_col,image_col]]
window = sg.Window('meme', layout,finalize=True)

while True:
    event, values = window.read()

    if event is None:
        break
    if event == '_3_':
        window['-IMAGE-'].update(get_data())

window.close()