How Can I Use Tkinter's `after` Method to Create a Simple Animation?

Tkinter — Executing Functions over Time

In event-driven programming, the application can schedule functions to run at specified times. Tkinter widgets have a after method that can be used to execute a function after a certain number of milliseconds has passed.

To make a rectangle blink three times, we need to write a function that changes the rectangle's fill color and schedule it to run three times at 1-second intervals. Here's how we can do it:

import tkinter as tk
from time import sleep

def blink(rect, canvas):
    for i in range(3):
        canvas.itemconfigure(rect, fill="red")
        sleep(1)
        canvas.itemconfigure(rect, fill="white")
        sleep(1)

root = tk.Tk()
fr = tk.Frame(root)
fr.pack()
canv = tk.Canvas(fr, height=100, width=100)
canv.pack()
rect = canv.create_rectangle(25, 25, 75, 75, fill="white")

# Schedule blink function to run
canv.after(1000, blink, rect, canv)
canv.after(2000, blink, rect, canv)
canv.after(3000, blink, rect, canv)

root.mainloop()

This code will create a rectangle and schedule it to change its fill color from white to red and back, three times at 1-second intervals.

The after method can also be used to schedule a function to run after a specified number of milliseconds, or it can be used to schedule a function to run repeatedly at a specified interval. This can be useful for creating animations or for periodically checking for new data.

The above is the detailed content of How Can I Use Tkinter's `after` Method to Create a Simple Animation?. For more information, please follow other related articles on the PHP Chinese website!