Android button event handler

Android Button Event Listeners and handlers

OnClickListner interface

public class MainActivity extends Activity implements OnClickListener {

  

    Context context;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        context = this;

   Button btn1 = (Button)findViewById(R.id.button1);

        btn1.setOnClickListener(this);

        Button btn2 = (Button)findViewById(R.id.button2);

        btn2.setOnClickListener(this);

        Button btn3 = (Button)findViewById(R.id.button3);

        btn3.setOnClickListener(this);

     }

     @Override

    public void onClick(View v) {

        // TODO Auto-generated method stub

        if(v.getId() == R.id.button1){

            Toast.makeText(context, "Button 1 Click", Toast.LENGTH_LONG).show();

        }

        else if(v.getId() == R.id.button2){

            Toast.makeText(context, "Button 2 Click", Toast.LENGTH_LONG).show();

        }

        else if(v.getId() == R.id.button3){

            Toast.makeText(context, "Button 3 Click", Toast.LENGTH_LONG).show();

        }

    }
}

 1- OnClick event for each View

OnClickListener()    //Event Listeners

When the User  click or touch upon any widget like Button, ImageButton, EditText, Image.

Button btn1 = (Button)findViewById(R.id.button1);

        btn1.setOnClickListener(new View.OnClickListener() {

             

            @Override

            public void onClick(View v) {

                // TODO Auto-generated method stub

                Toast.makeText(context, "Button click event handler", Toast.LENGTH_LONG).show();

            }

        });

OnClick Declaratively Event Handler
Instead of applying an OnClickListener to the button in your activity, you can assign a method to your button in the XML layout.
For example: XML file: Line # 6  using android:onClick (Button click event declaratively). For example

1.<Button

2.        android:id="@+id/button3"

3.        android:layout_width="300dp"

4.        android:layout_height="wrap_content"

5.        android:layout_gravity="center_horizontal"

6.        android:onClick="buttonClick"                             //Click Event Declaratively

7.        android:text="Button declaratively event handler" />

 
MainActivity.java

1.      public void buttonClick(View v) {

2.        Toast.makeText(this, "Button declaratively event handler", Toast.LENGTH_LONG).show();

3.    }

 

2- OnLongClick

OnLongClickListener() // Event Listeners

The user either click or touch upon any widget like Button, ImageButton, EditText, Image for one or more seconds to handle such event.