How to Handle the Window Close Event in Tkinter?

Handling Window Close Event in Tkinter

Managing user interactions is crucial in GUI programming. One essential event to handle is the window close event, which occurs when the user clicks the "X" button in the window's title bar. In Tkinter, this event can be handled using protocol handlers.

Protocol Handlers

Tkinter's WM_DELETE_WINDOW protocol represents the user explicitly closing the window through the window manager. By installing a handler for this protocol, you can define the desired behavior when this event occurs.

Installing a Handler

To install a handler for the WM_DELETE_WINDOW protocol, use the protocol method on a Tk or Toplevel widget. The syntax is as follows:

<code class="python">widget.protocol("WM_DELETE_WINDOW", callback)</code>

Where widget is the Tk or Toplevel widget whose close event you want to handle, and callback is the function to execute when the window is closed.

Example

The following code demonstrates how to handle the window close event in a Tkinter program:

<code class="python">import tkinter as tk
from tkinter import messagebox

# Create a Tk root window
root = tk.Tk()

# Define the callback function for the close event
def on_closing():
    # Prompt the user for confirmation before quitting
    if messagebox.askokcancel("Quit", "Do you want to quit?"):
        root.destroy()

# Install the handler for the window close event
root.protocol("WM_DELETE_WINDOW", on_closing)

# Start the Tkinter event loop
root.mainloop()</code>

In this example, when the user clicks the "X" button, a confirmation dialog appears prompting them to confirm quitting. If the user confirms, the destroy method is called to close the window. Otherwise, the event is ignored.

The above is the detailed content of How to Handle the Window Close Event in Tkinter?. For more information, please follow other related articles on the PHP Chinese website!