Скачать или смотреть How to Prevent Blinking Effect in React Native AppState Changes

Learn how to instantly update your view in React Native without any blinking effect when the app state changes.
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How to Prevent Blinking Effect in React Native AppState Changes

As mobile app developers, we often face the challenge of ensuring that user experience is seamless and uninterrupted. One common issue encountered in React Native is the blinking effect that appears when an app transitions from the background back to the foreground. This problem can lead to confusion or poor user experience as users see part of the previous screen momentarily before the new view is rendered. In this guide, we will address this issue specifically related to using AppState and provide a solution to enhance your application's responsiveness.

Understanding the AppState Challenges

When working with AppState in React Native, developers may run into a couple of limitations, especially on Android:

Limited States: The AppState on Android only indicates background and lacks an inactive state, meaning that your app can't apply new states before it transitions to the background.

Asynchronous State Updates: The setState method in React Native does not apply updates instantly. Consequently, there may be delays in visual updates, leading to that annoying blinking effect.

The Problem Scenario

The typical scenario involves trying to display a "LOCKED" overlay when the app comes back into the foreground. However, if the state update happens too late, the users may briefly see the main content behind the overlay, resulting in an undesirable visual behavior. Below is an example of how one might initially implement this functionality:

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

The Solution: State Change on Background Event

To mitigate the blinking when coming back to the active state, you can change the visibility of your lock view during the background state instead of waiting until the return to active. This minor adjustment can significantly improve the appearance of your app. Here's how you can implement this fix:

Updated Code Snippet

Below is the corrected version of the code, where the lock visibility is set when the next state is active:

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

Key Changes

Moved the state change for lockVisible to the condition before updating appStateVisible.

This adjustment ensures that when the app transitions back to active, the lock screen displays immediately, preventing the main content from being visible during this change.

Conclusion

By tweaking how and when your app updates its state in response to AppState changes, you can eliminate the flicker and provide users with a smooth experience. Always remember to test on different devices and various states to ensure your app performs optimally.

With these adjustments, you'll have a robust solution that enhances your application’s responsiveness. Happy coding!