Скачать или смотреть Resolving tkinter Progress Bar Updates When Window Loses Focus

Learn how to ensure your `tkinter` progress bar updates smoothly, even when the application's window loses focus. This guide provides a simple solution for a common issue in Python GUI applications.
---
This video is based on the question https://stackoverflow.com/q/62898749/ asked by the user 'Aphyd' ( https://stackoverflow.com/u/6592216/ ) and on the answer https://stackoverflow.com/a/62943738/ provided by the user 'Aphyd' ( https://stackoverflow.com/u/6592216/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: tkinter progress bar does not update when window loses focus

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding the Progress Bar Issue in tkinter

If you're working with tkinter, Python's standard GUI toolkit, you might have encountered a frustrating issue—your progress bar fails to update when the application's window is not in focus. This can be especially troubling when you rely on a progress bar to provide feedback during long-running tasks.

In this post, we'll explain the problem in more detail and walk through a solution that can help ensure your progress bar remains responsive, regardless of whether the window is in focus.

The Problem

As you've likely experienced, the issue arises when you trigger a long-running operation while using a tkinter progress bar. The basic code to implement a progress bar typically looks something like this:

[[See Video to Reveal this Text or Code Snippet]]

When you attempt to update the progress bar during a lengthy process, it works fine—until you switch to another application or minimize the window. When you return, you might notice that the progress bar has not updated at all during that time.

Why Does This Happen?

The main reason this occurs is due to how tkinter processes events. When the window is not focused, it may not be processing the necessary updates for the progress bar to reflect the changes. This means that unless the application regains focus, the visual elements will simply not refresh.

The Solution

Fortunately, there is a straightforward fix to ensure that your progress bar updates even when the window loses focus. The key is to update your progress bar using a different method.

Step-by-Step Fix

Locate the Part of Your Code Updating the Progress Bar: In your run function, you may initially have something like this to increment the progress bar:

[[See Video to Reveal this Text or Code Snippet]]

Change to a More Effective Update Method: The change you need to make is simple. Replace window.update_idletasks() with window.update(). This forces the entire window to refresh and process any updates, including your progress bar.

Revised Code:

[[See Video to Reveal this Text or Code Snippet]]

Why This Change Works

Using window.update() instead of window.update_idletasks() sends a signal to tkinter to update all aspects of the GUI, not just the idle tasks. This ensures that your progress bar receives attention even when the application doesn't have focus, maintaining the user experience you aim for.

Conclusion

Implementing this simple fix can significantly enhance the functionality of your tkinter applications. By ensuring that your progress bar updates consistently, you provide users with better feedback during lengthy processes, making your GUI applications more user-friendly and reliable.

If you're building a tkinter application and need a responsive progress bar, remember to use window.update() to keep everything in sync, even when you're multitasking with other applications. Happy coding!