In this article we will see how to override a key down action in Android. Android support several Key Events. They are mapped in the KeyEvent class. This object is used to report key and button events like KEYCODE_BACK, KEYCODE_HOME, … The complete list of event is showed in the Android Developer Reference. The simple example below shows how to override the Back Button action in order to call a specific Activity and not the previous one.

public class MyActivity extends ListActivity  {

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        // return to the App's Home Activity
        if ((keyCode == KeyEvent.KEYCODE_BACK)) {
            Intent intent = new Intent(this, MyBackActivity.class);
	    this.startActivity(intent);
        }
        return super.onKeyDown(keyCode, event);
    }
}