OnKeyListener

OnKeyListener: Interface definition for a callback to be invoked when a hardware key event is dispatched to this view. The callback will be invoked before the key event is given to the view. This is only useful for hardware keyboards; a software input method has no obligation to trigger this listener.

onKey (View v, int keyCode, KeyEvent event) :Called when a hardware key is dispatched to a view. This allows listeners to get a chance to respond before the target view.

keyCode: The code for the physical key that was pressed.

event: The KeyEvent object containing full information about the event.

MainActivity.java:

public class MainActivity extends Activity {

       EditText et;

             

       @Override

       protected void onCreate(Bundle savedInstanceState) {

              super.onCreate(savedInstanceState);

              setContentView(R.layout.activity_main);

             

              et = (EditText) findViewById(R.id.editText1);

             

              et.setOnKeyListener(new OnKeyListener() {

                    

                     @Override

                     public boolean onKey(View v, int keyCode, KeyEvent event) {

                          

                     if(keyCode == KeyEvent.KEYCODE_ENTER && event.getAction() == KeyEvent.ACTION_DOWN){

                                 

                                  Toast.makeText(MainActivity.this, "Welcome "+et.getText().toString() +"!", Toast.LENGTH_SHORT).show();

                           }

                          

                           return false;

                     }

              });

       }

       @Override

       public boolean onCreateOptionsMenu(Menu menu) {

              // Inflate the menu; this adds items to the action bar if it is present.

              getMenuInflater().inflate(R.menu.main, menu);

              return true;

       }

}

activity_main.xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context=".MainActivity" >

    <EditText

        android:id="@+id/editText1"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignParentTop="true"

        android:layout_centerHorizontal="true"

        android:layout_marginTop="38dp"

        android:ems="10" />

</RelativeLayout>