Creating fluid movement of an oval using tkinter

问题:

I'm trying to create Connect-Four using tkinter. Once a disc is placed in a certain column, I want it to descend to the bottom of the column in a fluid movement.

I've tried using the move command of the Canvas class but I'm unsure if I am using it incorrectly or perhaps I am better off deleting and re-drawing the oval each iteration. Currently, the disc indeed moves but not in a fluid way. It simply draws it in the new location.

This is the disc moving function:

        counter = 0
    self.__canvas.create_oval(100,200,0,100, fill='yellow')
    self.__canvas.create_oval(100,300,0,200, fill='yellow')
    self.__canvas.create_oval(100,400,0,300, fill='brown')
    disc = self.__canvas.create_oval(200,400,100,300, fill='green')  # trying to move this specific disc
    while counter < 10:
         self.__canvas.move(disc, 0, counter)
         counter += 1

回答1:

You must pace the calls to move so that the movement is visible; canvas.after() allows you to call a function repeatedly, in this case until a condition is met (the disk arrived at destination)

working code snippet

import tkinter as tk


def smooth_motion(counter):
     canvas.move(disc, 0, dy)
     counter -= 1
     if counter >= 0:
         canvas.after(10, smooth_motion, counter)

root = tk.Tk()
canvas = tk.Canvas(root, bg='cyan')
canvas.pack()

counter = 100
disc = canvas.create_oval(200, 0, 210, 10, fill='green')
dy = (100 - 0) / counter
smooth_motion(counter)

root.mainloop()

回答2:

You're missing function which shows changes to canvas - canvas.update(), try writing it after canvas.move().