Скачать или смотреть How to Fix PlatformException in Flutter's Local Authentication

Struggling with `PlatformException(no_fragment_activity)` while using fingerprint authentication in Flutter? Learn how to resolve this issue effectively.
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How to Fix PlatformException in Flutter's Local Authentication

As a beginner in Flutter, you may encounter various challenges while integrating features into your application. One common issue is related to fingerprint authentication using the local_auth plugin. You might see an error message like:

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

In this guide, we will dive deep into this problem and provide you with a step-by-step solution so you can smoothly implement fingerprint authentication in your Flutter app.

Understanding the Problem

The PlatformException(no_fragment_activity) error typically occurs because the local_auth plugin requires the parent activity to be of type FragmentActivity instead of the default FlutterActivity. This is a requirement for the library to function properly.

Let's look at how to resolve this issue efficiently.

Step-by-Step Solution

1. Add Required Permissions

Before making any changes to your activity, ensure that you have the necessary permissions added to your Android AndroidManifest.xml file:

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

Adding this permission will allow your application to utilize fingerprint authentication functionalities.

2. Change Activity from FlutterActivity to FlutterFragmentActivity

You need to change your MainActivity class from extending FlutterActivity to extending FlutterFragmentActivity.

Here is how you can do that:

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

This alteration enables the local_auth plugin to utilize the fragment capabilities necessary for fingerprint authentication.

3. Addressing Theme Issues

If you encounter any issues related to themes such as:

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

You can fix it by editing your style.xml file.

Navigate to:

android>app>src>main>res>values>style.xml

Make sure your LaunchTheme style looks like this:

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

This change assigns an AppCompat theme that is compatible with the FragmentActivity, resolving the theme-related error.

Conclusion

Integrating fingerprint authentication into your Flutter app can be a straightforward process if you are aware of the requirements and common pitfalls. By making the adjustments outlined above—adding the proper permissions, changing the activity type, and addressing any theme issues—you will be well on your way to having a functional fingerprint authentication feature in your application.

If you have any more questions or run into further issues, feel free to leave a comment below. Happy coding!