绘制动画

例1：

from tkinter import Canvas,mainloop,Tk
import numpy as np
import random
import traceback
import threading
import time
from queue import Queue

class Point:
    def __init__(self,the_canvas,uID):
        self.uID = uID
        self.location = np.ones((2)) * 200
        self.color = "#"+"".join([random.choice('0123456789ABCDEF') for j in range(6)])
        self.the_canvas = the_canvas
        self.the_canvas.create_oval(200,200,200,200,
                     fill=self.color,outline=self.color,width=6,
                     tags=('runner'+str(self.uID),'runner'))
    def move(self):
        delta = (np.random.random((2))-.5)*20
        self.the_canvas.move('runner'+str(self.uID),delta[0],delta[1])

def queue_func():
    while True:
        time.sleep(.25)
        try:
            next_action = the_queue.get(False)
            next_action()
        except Exception as e: 
            if str(e) != "": 
                print(traceback.format_exc())

the_queue = Queue()
the_thread = threading.Thread(target=queue_func)
the_thread.daemon = True
the_thread.start()

window = Tk()
window.geometry('400x400')
the_canvas = Canvas(window,width=400,height=400,background='black')
the_canvas.grid(row=0,column=0)

points = {}
for i in range(100):
    points[i] = Point(the_canvas,i)

def random_movement():
    for point in points.values():
        point.move()
    window.after(150, random_movement)

the_queue.put(random_movement)

mainloop()

例2：

import tkinter as tk

TOKENWIDTH = 10

class Example(tk.Frame):
    '''Illustrate how to drag items on a Tkinter canvas'''

    def __init__(self, parent):
        tk.Frame.__init__(self, parent)

        # create a canvas
        self.canvas = tk.Canvas(width=400, height=400, bg="white")
        self.canvas.pack(fill="both", expand=True)

        # this data is used to keep track of an
        # item being dragged
        self._drag_data = {"x": 0, "y": 0, "item": None}

        # create a couple of movable objects
        self._create_token((100, 100), "red")
        self._create_token((200, 100), "black")

        # add bindings for clicking, dragging and releasing over
        # any object with the "token" tag
        self.canvas.tag_bind("token", "<ButtonPress-1>", self.on_token_press)
        self.canvas.tag_bind("token", "<ButtonRelease-1>", self.on_token_release)
        self.canvas.tag_bind("token", "<B1-Motion>", self.on_token_motion)

    def _create_token(self, coord, color):
        '''Create a token at the given coordinate in the given color'''
        (x,y) = coord
        self.canvas.create_oval(x-25, y-25, x+25, y+25,
                                outline="blue", fill=color, tags="token", width = TOKENWIDTH)

    def on_token_press(self, event):
        '''Begining drag of an object'''
        # record the item and its location
        self._drag_data["item"] = self.canvas.find_closest(event.x, event.y)[0]
        self._drag_data["x"] = event.x
        self._drag_data["y"] = event.y
        self.canvas.update_idletasks()

    def on_token_release(self, event):
        '''End drag of an object'''
        # reset the drag information
        self._drag_data["item"] = None
        self._drag_data["x"] = 0
        self._drag_data["y"] = 0
        self.canvas.update_idletasks()

    def on_token_motion(self, event):
        '''Handle dragging of an object'''
        # compute how much the mouse has moved
        delta_x = event.x - self._drag_data["x"]
        delta_y = event.y - self._drag_data["y"]
        # move the object the appropriate amount
        self.canvas.move(self._drag_data["item"], delta_x, delta_y)
        # record the new position
        self._drag_data["x"] = event.x
        self._drag_data["y"] = event.y
        self.canvas.update_idletasks()

if __name__ == "__main__":
    root = tk.Tk()
    Example(root).pack(fill="both", expand=True)
    root.mainloop()