Fragment implenets View.OnClickListener - button doesn't work

Question

Why doesn't my button show toast message and writes to the log. The button is inside the fragment?

Code inside my MainActivity.java

 public class MainActivity extends AppCompatActivity {

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
        }

Code inside my FragmentA.java:

    public class FragmentA extends Fragment implements   View.OnClickListener{

    Button button;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_a, container, false);
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        button = (Button)getActivity().findViewById(R.id.button);
    }

    @Override
    public void onClick(View view) {
        Toast.makeText(getActivity(), "Do it", Toast.LENGTH_LONG).show();
        Log.w("myApp","Hi there");
    }
}

Code inside fragment_a.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#FFBB00"
    >


    <Button
        android:layout_margin="40dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="New Button"
        android:id="@+id/button"
        />

</LinearLayout>

Code inside activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#00BBFF"
    >


    <fragment
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:name="com.example.audiorecbas.audio_recorder_basic.FragmentA"
        android:id="@+id/fragment"
        android:layout_alignParentTop="true"
        android:layout_alignParentStart="true" />
</RelativeLayout>

Answer 1

  @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        button = (Button)getActivity().findViewById(R.id.button);
        button.setOnClickListener(this);
    }

Answer 2

In your Fragment Java class, you need to have the following to handle the Button's click event: Like this way

    public class FragmentA extends Fragment implements   View.OnClickListener
    {
           Button btn;

         @Override
         public void onActivityCreated(Bundle savedInstanceState) {
         super.onActivityCreated(savedInstanceState);

                btn = (Button) getActivity().findViewById(R.id.button);
                btn.setOnClickListener(this);       

            ......    
            }

For better information please check SO ANSWER

Answer 3

You haven't linked the button's onClickListener after instantiating it.

button = (Button) getActivity.findViewById(R.id.button);
button.setOnClickListener(this); //add this

Answer 4

Remove this entire code

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    button = (Button)getActivity().findViewById(R.id.button);

}

then add

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_a, container, false);
    button= (Button) view.findViewById(R.id.button);
    button.setOnClickListener(this);
    return view;
}

@Override
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.button:
            {
             //Do your stuff here
            }
         }
      }