基于 Python 的 MS 画图应用程序 - 无法保存图片

Question

我正在尝试创建一个类似 Paint 的基于 Python 的应用程序。我曾尝试实现一个保存功能，但它似乎只保存背景/墙纸而不是绘图本身。任何解决此问题的帮助将不胜感激。我在 MacOS 13.3.1 上使用 PyCharm CE。这是我到目前为止所做的：

import tkinter as tk
from tkinter import messagebox
from tkinter import filedialog
from tkinter import colorchooser
from PIL import Image
from PIL import ImageGrab
class PaintApp:
    def __init__(self):
        self.root = tk.Tk()
        self.root.title("Paint App")
        # Get the screen resolution
        screen_width = self.root.winfo_screenwidth()
        screen_height = self.root.winfo_screenheight()

        # Set the size of the main window
        width = int(screen_width * 1.0)
        height = int(screen_height * 1.0)
        self.root.geometry(f"{width}x{height}")

        self.canvas = tk.Canvas(self.root, bg="white")
        self.canvas.pack(fill="both", expand=True)
        self.brush_color = 'black'
        self.brush_size = 2
        self.canvas.bind('<B1-Motion>', self.draw)

        self.color_selector = tk.Frame(self.root, pady=10)
        self.color_selector.pack()

        self.color_label = tk.Label(self.color_selector, text='Brush Colour')
        self.color_label.pack(side='left', padx=5)

        self.red_button = tk.Button(self.color_selector, bg='red', width=2, command=lambda:self.set_brush_color('red'), highlightbackground='red')
        self.red_button.pack(side='left', padx=5)
        self.green_button = tk.Button(self.color_selector, bg='green', width=2, command=lambda:self.set_brush_color('green'), highlightbackground='green')
        self.green_button.pack(side='left', padx=5)
        self.blue_button = tk.Button(self.color_selector, bg='blue', width=2, command=lambda:self.set_brush_color('blue'), highlightbackground='blue')
        self.blue_button.pack(side='left', padx=5)
        self.yellow_button = tk.Button(self.color_selector, bg='yellow', width=2, command=lambda: self.set_brush_color('yellow'), highlightbackground='yellow')
        self.yellow_button.pack(side='left', padx=5)
        self.orange_button = tk.Button(self.color_selector, bg='orange', width=2, command=lambda: self.set_brush_color('orange'), highlightbackground='orange')
        self.orange_button.pack(side='left', padx=5)

        self.size_selector = tk.Frame(self.root, pady=10)
        self.size_selector.pack()
        self.color_label = tk.Label(self.size_selector, text='Brush Size')
        self.color_label.pack(side='left', padx=5)
        self.small_button = tk.Button(self.size_selector, text='Small', width=8, command=lambda:self.set_brush_size(2), highlightbackground= 'white')
        self.small_button.pack(side='left', padx=5)
        self.medium_button = tk.Button(self.size_selector, text='Medium', width=8, command=lambda:self.set_brush_size(5), highlightbackground='white')
        self.medium_button.pack(side='left', padx=5)
        self.large_button = tk.Button(self.size_selector, text='Large', width=8, command=lambda:self.set_brush_size(10), highlightbackground='white')
        self.large_button.pack(side='left', padx=5)

        self.eraser_button = tk.Button(self.root, text='Eraser', width=10, command=self.set_brush_to_white)
        self.eraser_button.pack(side='right', padx=10, pady=10)

        self.save_button = tk.Button(self.root, text='Save', width=8, command=self.save_drawing, relief='solid')
        self.save_button.pack(side='right', padx=10, pady=10)

    def save_drawing(self):
        file_path = filedialog.asksaveasfilename(defaultextension='.png')
        if file_path:
            x = self.root.winfo_rootx() + self.canvas.winfo_x()
            y = self.root.winfo_rooty() + self.canvas.winfo_y()
            x1 = x + self.canvas.winfo_width()
            y1 = y + self.canvas.winfo_height()
            img = ImageGrab.grab().crop((x, y, x1, y1))
            img.save(file_path)

    def draw(self, event):
        x1, y1 = (event.x - self.brush_size), (event.y - self.brush_size)
        x2, y2 = (event.x + self.brush_size), (event.y + self.brush_size)
        self.canvas.create_oval(x1, y1, x2, y2, fill=self.brush_color, outline=self.brush_color)

    def set_brush_color(self, color):
        self.brush_color = color

    def set_brush_size(self, size):
        self.brush_size = size
        self.small_button['relief'] = 'raised'
        self.medium_button['relief'] = 'raised'
        self.large_button['relief'] = 'raised'
        if size == 2:
            self.small_button['relief'] = 'sunken'
        elif size == 5:
            self.medium_button['relief'] = 'sunken'
        elif size == 10:
            self.large_button['relief'] = 'sunken'

    def set_brush_to_white(self):
        self.brush_color = 'white'

    def run(self):
        self.root.mainloop()

if __name__ == '__main__':
    app = PaintApp()
    app.run()

我尝试保存，但输出文件只显示屏幕壁纸，就好像应用程序/绘图是不可见的。我尝试使用 postscript，但它似乎不适用于 MacOS。