ViewModelProviders.of(this)

The ViewModelProviders.of(this) method is used to retrieve a ViewModelProvider for the given FragmentActivity or Fragment. This method is used to retrieve a ViewModel instance for a given FragmentActivity or Fragment. By using ViewModelProviders.of(this).get(ViewModel.class), we retrieve a ViewModel that is scoped to the FragmentActivity or Fragment. This means that the ViewModel will be retained even when the FragmentActivity or Fragment is recreated.

Why use ViewModelProviders.of(this)?

In Android, when the Fragment or Activity is recreated on configuration changes, the data that was being displayed is lost. This is a big problem when you are dealing with a lot of data that needs to be displayed in the UI. With ViewModelProviders.of(this), we can solve this problem by retaining the data across configuration changes.

The ViewModel class is designed to store and manage UI-related data in a lifecycle-conscious way. The ViewModel class allows data to survive configuration changes such as screen rotations.

By using ViewModelProviders.of(this), we can ensure that the ViewModel instance is retained across configuration changes, so the data will not be lost.

How to use ViewModelProviders.of(this)?

To use ViewModelProviders.of(this), you first need to add the ViewModel dependency to your project. Here's how to add the ViewModel dependency:

dependencies {
    def lifecycle_version = "2.2.0"
    implementation "androidx.lifecycle:lifecycle-viewmodel:$lifecycle_version"
}

After adding the ViewModel dependency, you can use ViewModelProviders.of(this) to retrieve the ViewModel instance. Here's an example:

public class MyFragment extends Fragment {

    private MyViewModel viewModel;

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
        viewModel = ViewModelProviders.of(this).get(MyViewModel.class);
    }
}

In this example, we retrieve the ViewModel instance by passing the Fragment instance to the ViewModelProviders.of(this) method. We then call the get() method, passing in the ViewModel class as a parameter.

Conclusion

In this tutorial, we learned about the ViewModelProviders.of(this) method, which is used to retrieve a ViewModelProvider for the given FragmentActivity or Fragment. We also learned about the benefits of using the ViewModel class in Android development, and how to use ViewModelProviders.of(this) to retrieve a ViewModel instance that will be retained across configuration changes.

By using ViewModelProviders.of(this), we can ensure that our ViewModel instance is retained across configuration changes, so our data will not be lost. This makes our app more robust and user-friendly, and helps us create a better user experience.