如何使用Tkinter更新图片？

Question

I've been having a problem with updating a picture in python using Tkinter. This program is creating a QR code and is displaying it on the window. I have no idea how to update it when it changes, the file name stays the same it just changes. This is what activates the creation of a QR code

def GenerateQRCode():
    # qr code maker 3000
    qr = qrcode.QRCode()
    qr.add_data("brush")
    img = qrcode.make(input.get())
    img.save("qrcode.png")
    resize_image = img.resize((150, 150))
    img2 = ImageTk.PhotoImage(img)
    label1 = Label(root, image=img2)
    label1.image = img2
    label1.pack(pady=50)

It does the job of creating the QR code and dispalying it, however, like I said, no clue how to update it while the file name would stay the same. I could make qrcode1.png, then if new QR code is requested, check if it exists, if so, delete it and make qrcode2.png and display it, viceversa. But I'm sure there is a way how to do it with just one file and maybe even creating the file might be unnecessary. Any comment is welcome. Thank you.

Answer 1

You should create the label with the qr code once, and then update the label whenever you create the new qr code. Here's an example based off of your code:

import tkinter as tk
import qrcode
from PIL import ImageTk

def GenerateQRCode():
    global qr_image

    qr = qrcode.QRCode()
    qr.add_data("brush")
    img = qrcode.make(input.get())
    img.save("qrcode.png")

    resize_image = img.resize((150, 150))
    qr_image = ImageTk.PhotoImage(img)
    qr_label.configure(image=qr_image)

root = tk.Tk()
input = tk.Entry(root)
qr_image = tk.PhotoImage()
qr_label = tk.Label(root, image=qr_image, width=300, height=300)
button = tk.Button(root, text="Generate code", command=GenerateQRCode)

input.pack(side="top", fill="x")
qr_label.pack(side="top")
button.pack(side="bottom")

root.mainloop()