如何更新画布图像？

Question

import tkinter as tk
from PIL import Image, ImageTk, ImageEnhance
import pygame, pyautogui
pygame.init()

# Initialize the main window
window = tk.Tk()
window.geometry("776x582")
window.resizable(0, 0)
window.config(cursor="@NORMAL.cur")
#canvas
canvas = tk.Canvas(window, width=776, height=582)
canvas.place(x=0, y=0, anchor=tk.NW)
background_image = tk.PhotoImage(file="bg.png")
canvas.create_image(0, 0, image=background_image, anchor=tk.NW, tags="background")

img1 = Image.open("char1.png").convert("RGBA")
img2 = Image.open("char2.png").convert("RGBA")
char1_img = ImageTk.PhotoImage(img1)
char2_img = ImageTk.PhotoImage(img2)
char1 = canvas.create_image(176, 250,image=char1_img,anchor=tk.NW)
char2 = canvas.create_image(200, 200,image=char2_img,anchor=tk.NW)


def brightness(image,val):
    return ImageEnhance.Brightness(image).enhance(val)

def character(canv,char_x, char_y, char_w, char_h,img,char_img,char):

    #character
    img = brightness(img,1)
    
    canv.itemconfig(char,image=char_img)

    def motion(event,img):
        x, y = event.x, event.y
        if char_x < x < char_x + char_w and char_y < y < char_y + char_h:
            img = brightness(img,1.3)
            char_img = ImageTk.PhotoImage(img)
            
        else:
            img = brightness(img,1)
            char_img = ImageTk.PhotoImage(img)
            
        canv.itemconfig(char, image=char_img)


    canv.bind('<Motion>', lambda event:motion(event,img))

#characters
character(canvas,176, 250, 103, 213,img1,char1_img,char1)

window.mainloop()

如果鼠标进入，我想更改img的亮度，但是当我更改它时，img没有更新idk为什么，我尝试使用.itemconfig（并在那里指定明亮的图像），我希望你们帮助我出来了。

Answer 1

分配给函数内局部变量的图像将在退出函数后被垃圾收集。

建议使用类和实例变量来存储图像：

class Character:
    def __init__(self, canv, img, char):
        self._canv = canv
        self._img = img
        self._char = char

        canv.tag_bind(char, "<Enter>", lambda e: self.set_brightness(1.3))
        canv.tag_bind(char, "<Leave>", lambda e: self.set_brightness(1))

    def set_brightness(self, level):
        img = brightness(self._img, level)
        # use instance variable to store the image reference
        # to prevent the image from garbage collection
        self._photo = ImageTk.PhotoImage(img)
        self._canv.itemconfig(self._char, image=self._photo)


#characters
Character(canvas, img1, char1)