Android Data Binding pass arguments to onClick method

You can use a lambda expressions and pass the view in as a parameter.

 android:onClick="@{() -> callback.onCategoryClick(viewModel)}"

If you need the view, you can pass that as well with:

 android:onClick="@{(view) -> callback.onCategoryClick(view, viewModel)}"

Multiple Ways:

Solution 1 (When you have Presenter)

You have a presenter or handler class like below

public class Presenter {    public void onSaveClick(View view, Task task){}}

Now take variable of type Presenter in your layout. and set click like below.

<?xml version="1.0" encoding="utf-8"?><layout xmlns:android="http://schemas.android.com/apk/res/android">    <data>        <variable name="task" type="com.android.example.Task" />        <variable name="presenter" type="com.android.example.Presenter" />    </data>    <LinearLayout ...>        <Button            android:layout_width="wrap_content"            android:layout_height="wrap_content"           android:onClick="@{(view) -> presenter.onSaveClick(view, task)}"           />    </LinearLayout></layout>

You can add any more arguments in this.

Please note that, you have to set these data variables in the onCreate() method. Like below

ActivityMainBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_main);binding.setTask(task);binding.setPresenter(presenter);

Solution 2 (When you don't have Presenter)

Create a variable type of your Activity / Fragment

<?xml version="1.0" encoding="utf-8"?><layout xmlns:android="http://schemas.android.com/apk/res/android">    <data>        <variable name="task" type="com.android.example.Task" />        <variable name="activity" type="com.example.MainActivity" />    </data>    <LinearLayout ...>        <Button            android:layout_width="wrap_content"            android:layout_height="wrap_content"           android:onClick="@{(view) -> activity.onSaveClick(view, task)}"           />    </LinearLayout></layout>

and make method in your activity which you want to call from binding layout. and don't forget to call setActivity(YourActivity.this) from Activity.

public class MainActivity extends AppCompatActivity {    public void onSaveClick(View view, Task task) {        System.out.println("MainActivity.onSaveClick");    }    @Override    protected void onCreate(@Nullable Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        ActivityMainBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_main);        binding.setActivity(this);        binding.setTask(task);    }}

Further reading Android DataBinding documentation

There are many other ways to set click, check this answer.