Скачать или смотреть Removing a Row from RecyclerView Using Room

Discover effective steps to successfully delete rows from RecyclerViews linked with Room database in Android. Get rid of UI glitches and potential crashes while achieving smooth data handling!
---
This video is based on the question https://stackoverflow.com/q/63266686/ asked by the user 'android dev' ( https://stackoverflow.com/u/14046751/ ) and on the answer https://stackoverflow.com/a/63491438/ provided by the user 'Karthik Kompelli' ( https://stackoverflow.com/u/3861913/ ) 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: How do I remove a row from recyclerview using room?

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.
---
How to Remove a Row from RecyclerView Using Room

If you're developing an Android app and using RecyclerView to display data contained in a Room database, you may find yourself needing to delete individual items from this list. A typical user experience involves swiping to delete a row, but achieving this operation seamlessly requires some attention to your implementation. In this guide, we will guide you through the necessary steps to effectively remove a row from a RecyclerView that utilizes the Room database.

The Challenge

You might want to delete a particular item from the RecyclerView and Room database upon swipe action. However, the problem arises when the deleted item reappears upon revisiting the activity. This problem typically stems from not correctly removing the item from the database.

Step-by-Step Solution

Let's break down the solution into clear, organized sections that encourage good coding practices and efficient handling of data.

Step 1: Verify CustomApplication Configuration

Ensure that your CustomApplication class is correctly defined in the AndroidManifest.xml. The entry should look like this:

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

This is important to avoid runtime issues, such as ClassCastException when casting the application.

Step 2: Update Gradle Configuration

In your module-level build.gradle, make sure you include:

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

Correctly setting these dependencies allows Room to create the necessary database implementation.

Step 3: Add Deletion Method in AddressDao

Ensure your AddressDao interface includes a delete method that looks like this:

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

This method is crucial for removing the item from the database.

Step 4: Implement Item Listener in Adapter

Introduce an item click listener in your AddressAdapter. This pattern allows for better separation between the RecyclerView and the Activity's logic.

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

Step 5: Modify Delete Action in Adapter

In your tvDelete.setOnClickListener, call the listener's method instead of handling the database deletion directly:

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

Step 6: Implement Listener in AddressActivity

In your AddressActivity class, extend the listener implementation:

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

Step 7: Handle Background Execution Correctly

To avoid blocking the UI, wrap your delete calls inside a coroutine using lifecycleScope. Make sure to include necessary dependencies for coroutines in your build.gradle:

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

Final Note on Main Thread Execution

If you wish to execute database operations directly on the main thread for rapid development, you can adjust your Dao and database setup. However, this is not recommended for production applications due to potential UI freezes.

To allow main thread queries, add:

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

to your database builder in CustomApplication.

Conclusion

By following these steps, you can efficiently manage row deletions from your RecyclerView and persist such changes in your Room database. Proper implementation of item listeners ensures clear separation of concerns and enhances maintainability. Always remember, handling database operations in a background thread is vital to maintaining a responsive UI.

Feel free to reach out with any questions or share your own experiences in handling RecyclerView deletions. Happy coding!