如何在tkinter python中使按钮的背景颜色闪烁

Question

I have a simple window with 2 buttons and one entry. I want to make the button2 flashing (blinking) if the text from entry is the same with the text on button2. Try to using after function but not get any luck. I can change the color but don't know how to make it flashing. Here is my code:

import tkinter as tk

text = ""
def gettext():
    text = entry.get()
    if text == button2['text']:
        button2.config(background='red')
        
root = tk.Tk()
entry = tk.Entry(root)
entry.pack()
button1 = tk.Button(root, text="Text", command=gettext)
button1.pack(side="bottom", padx=20, pady=20)
button2 = tk.Button(root, text="Flashing")
button2.pack(side="bottom", padx=20, pady=20)
root.mainloop()

Answer 1

Try this:

import tkinter as tk

text = ""
def gettext(*args):
    text = entry.get()
    if text == button2.cget("text"):
        # Change the button's bg to red
        button2.config(background="red")
        # After 100ms reset the variable's bg
        button2.after(100, lambda: button2.config(background="#f0f0ed"))
        # After 100 more milliseconds call `gettext` again
        button2.after(200, gettext)

root = tk.Tk()
# Create a StringVar variable
variable = tk.StringVar(root)
# Trace the variable
variable.trace("w", gettext)
# Attach it to the entry
entry = tk.Entry(root, textvariable=variable)
entry.pack()
button2 = tk.Button(root, text="Flashing")
button2.pack()
root.mainloop()

I removed one of the buttons and added a StringVar instead (to make it easier to test). The logic is quite simple:

• Change the button's bg to red
• Wait 100 milliseconds, reset the button's bg
• After 100 more milliseconds, run the function again