Скачать или смотреть How to Fix the Flutter Bottom Navigation Bar Not Switching Screens Issue

Discover how to resolve the issue of the Flutter Bottom Navigation Bar not switching screens smoothly in your projects. Learn the necessary code corrections here!
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This video is based on the question https://stackoverflow.com/q/73299266/ asked by the user 'Furanzux Pocha' ( https://stackoverflow.com/u/19730912/ ) and on the answer https://stackoverflow.com/a/73299285/ provided by the user 'Md. Yeasin Sheikh' ( https://stackoverflow.com/u/10157127/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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How to Fix the Flutter Bottom Navigation Bar Not Switching Screens Issue

If you are new to Flutter and trying to implement a bottom navigation bar for the first time, you may have encountered a frustrating problem: tapping the navigation icons does not switch the screens as expected. It can be quite confusing, especially when following a guide that seems to work perfectly. In this guide, we will explore why this issue occurs and how to fix it.

Understanding the Problem

When implementing a bottom navigation bar in Flutter, it is common to define a stateful widget to manage the navigation. However, if the variable responsible for tracking the selected page (commonly pageIndex) is not correctly placed within the code structure, it may lead to unexpected behavior.

In our example, if pageIndex is defined inside the build method, it is reset to its initial value whenever the build method is called. This means that no matter how many times you tap the navigation items, the app will always revert to the initial screen.

Solution: Correctly Positioning pageIndex

To resolve the issue of the bottom navigation bar not switching screens, you should place the pageIndex variable outside of the build method. By defining it at the class level, it maintains its state between builds, allowing the app to remember which screen was previously selected.

Here’s how to implement the fix:

Define pageIndex at the Class Level

Move the pageIndex variable declaration up to the class level, before the build method. This ensures that it retains its value across state updates.

Initialize Your Pages Outside of build

You can also initialize your list of pages outside the build method to make the code cleaner.

Example Code

Here is the corrected version of your original NavBar code:

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

Conclusion

By modifying where you define your pageIndex, you can easily solve the problem of the bottom navigation bar not switching screens in Flutter. This adjustment allows the app to properly maintain the selected screen state as you tap different icons.

Feel free to reach out if you have any additional questions or need further assistance with your Flutter projects. Happy coding!