View Binding in Android: Activities, Fragments, Dialogs, and RecyclerView Adapters

Whenever we start a project the most monotonous work is to initialize each of the views from our layout files and using findViewById again and again. For a long time, we have been doing this but now ViewBinding can save your time.

What is View Binding? According to the official documentation

View binding is a feature that allows you to more easily write code that interacts with views. Once view binding is enabled in a module, it generates a binding class for each XML layout file present in that module. An instance of a binding class contains direct references to all views that have an ID in the corresponding layout.

In short its a replacement for our old friend findViewById.

Why use View Binding:

• Null safety
• Type safety
• Faster compilation
• Ease of use

To use View Binding in your projects your Android Studio version should be at least 3.6.

In your build.gradle file add the following code:

android{
... 
   viewBinding {
      enabled = true
   }
}

From Android Studio version 4.0 use the following code:

android{
... 
    buildFeatures {
        viewBinding = true
    }
}

Let's see how itis implemented.

I am adding all the XML files here and you can see that I haven't done anything special here everything is what we do normally.

We usually use layout files in

• Activities
• Fragments
• Dialogs
• Recycler View Adapters

Let's take each one of them one by one.

In Activities:

To use view binding in activities add the following code instead of setContentView(R.layout.some_layout)

public class MainActivity extends AppCompatActivity {
    ActivityMainBinding binding;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = ActivityMainBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());


        binding.greetingText.setText("Hello, Reader.");
  }
}

Now you can access any view added in your activity_main.xml file. For example to get a reference of the TextView use binding.greetingText and all the methods available for a TextView will be available to you.

In Fragments:

In the onCreateView() method use the following code:

private FragementLayoutBinding binding;
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
  binding = FagementLayoutBinding.inflate(inflater,container,false);
  View view  = binding.getRoot();
  return view;
}

In DialogFragments:

In onCreateDialog() method set the custom views by the following code:

public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {

    binding = DialogLayoutBinding
              .inflate(LayoutInflater.from(getContext()));
AlertDialog.Builder builder = new AlertDialog.Builder(getContext());
    builder.setView(binding.getRoot());

    binding.dialogTextView.setText("I am Dialog's TextView");

    return builder.create();
}

In RecyclerViewAdapters:

In onCreateViewHolder method add the view like this:

public CustomViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    LayoutInflater inflater = LayoutInflater.from(mContext);
    binding = ListItemBinding.inflate(inflater,parent,false);
    return new CustomViewHolder(binding);
}

Also in your custom class extending ViewHolder class add the following code:

public class CustomViewHolder extends RecyclerView.ViewHolder{
    private ListItemBinding itemBinding;

    public CustomViewHolder(ListItemBinding itemBinding) {
        super(itemBinding.getRoot());
        this.itemBinding = itemBinding;
    }
}

Here’s the MainActivity

Now run the app and you will something like this:-

Also if you want a layout file to be ignored while generating binding classes, add the tools:viewBindingIgnore="true" attribute to the root view of that layout file.

You can check out this project from here

abhinav0612/ViewBinding