Simple drawing board made by Python function

Libraries that may need to be installed

pip install pillow
pip install tk

make

A simple painting software we created using Python's Tkinter library.

First, a simple painting application is created, which can select colors, switch between brush and eraser modes, clear the canvas, and draw free curves.

The main structure and functions inside are:

1. Import the necessary libraries:

   • tkinter: Used to create GUIs.
   • PIL(Python Imaging Library): Used to process images.

2. Define PaintAppthe class to build the painting application:

   • Initialize interface and properties, such as pen color, eraser color, coordinates, etc.
   • Create canvases and buttons, and set button functions.

3. Method explanation:

   • choose_color(): Opens a color picker to let the user choose a brush color.
   • toggle_eraser(): Switch between brush mode and eraser mode, and update the button text.
   • clear_canvas(): Clears all content on the canvas.
   • start_paint(event): Record the position of the mouse button, used to draw a continuous curve.
   • paint(event): Draw lines according to the position of the mouse, which can be in brush mode or eraser mode.
   • end_paint(event): When the mouse is released, reset the drawing state.

4. Creates rootthe window, instantiates PaintAppthe class, and starts the main event loop.

Users can select colors with the click of a button, switch between brush and eraser modes, draw freeform curves, and clear the canvas when needed. The interface and interaction logic of the entire application are controlled by code.

source code:

import tkinter as tk
from tkinter import ttk
from tkinter.colorchooser import askcolor
from tkinter import messagebox
from PIL import Image, ImageDraw

class PaintApp:
    def __init__(self, root):
        self.root = root
        self.root.title("绘画软件")

        self.pen_color = "black"
        self.eraser_color = "white"  # 橡皮擦的颜色
        self.old_x = None
        self.old_y = None
        self.eraser_mode = False

        self.canvas = tk.Canvas(root, bg="white", width=600, height=400)
        self.canvas.pack()

        self.button_frame = ttk.Frame(root)
        self.button_frame.pack(pady=10)

        self.pen_button = ttk.Button(self.button_frame, text="选择颜色", command=self.choose_color)
        self.pen_button.grid(row=0, column=0)

        self.eraser_button = ttk.Button(self.button_frame, text="橡皮擦", command=self.toggle_eraser)
        self.eraser_button.grid(row=0, column=1)

        self.clear_button = ttk.Button(self.button_frame, text="清空画布", command=self.clear_canvas)
        self.clear_button.grid(row=0, column=3)

        self.canvas.bind("<Button-1>", self.start_paint)
        self.canvas.bind("<B1-Motion>", self.paint)
        self.canvas.bind("<ButtonRelease-1>", self.end_paint)

    def choose_color(self):
        color = askcolor(color=self.pen_color)[1]
        if color:
            self.pen_color = color

    def toggle_eraser(self):
        self.eraser_mode = not self.eraser_mode
        if self.eraser_mode:
            self.eraser_button.config(text="画笔模式")
        else:
            self.eraser_button.config(text="橡皮擦")

    def clear_canvas(self):
        self.canvas.delete("all")

    def start_paint(self, event):
        self.old_x = event.x
        self.old_y = event.y

    def paint(self, event):
        if self.old_x and self.old_y:
            x, y = event.x, event.y
            if self.eraser_mode:
                self.canvas.create_line(self.old_x, self.old_y, x, y, fill=self.eraser_color, width=10, capstyle=tk.ROUND, smooth=tk.TRUE)
            else:
                self.canvas.create_line(self.old_x, self.old_y, x, y, fill=self.pen_color, width=2, capstyle=tk.ROUND, smooth=tk.TRUE)
            self.old_x = x
            self.old_y = y

    def end_paint(self, event):
        self.old_x = None
        self.old_y = None

if __name__ == "__main__":
    root = tk.Tk()
    app = PaintApp(root)
    root.mainloop()

Effect