[Android] controls and basic event response methods

The first method is [java] package com. app; import android. OS. bundle; import android. app. activity; import android. content. intent; import android. view. motionEvent; import android. view. view; import android. view. view. onClickListener; import android. widget. button; public class MainActivity extends Activity {protected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. activity_main); Button button = (Button) findViewById (R. id. button1); button. setOnClickListener (new OnClickListener () {@ Override public void onClick (View v) {// TODO Auto-generated method stub Intent intent = new Intent (MainActivity. this, SecondActivity. class); startActivity (intent) ;}}}} method 2 [java] package com. app; import android. app. activity; import android. content. intent; import android. OS. bundle; import android. view. view; import android. view. view. onClickListener; import android. widget. button; public class SecondActivity extends Activity implements OnClickListener {private Button button1; @ Override protected void onCreate (Bundle savedInstanceState) {// TODO Auto-generated method stub super. onCreate (savedInstanceState); setContentView (R. layout. activity_welcome); button1 = (Button) findViewById (R. id. button1); button1.setOnClickListener (this) ;}@ Override public void onClick (View v) {// TODO Auto-generated method stub switch (v. getId () {case R. id. button1: Intent intent = new Intent (); intent. setClass (SecondActivity. this, ThirdActivity. class); startActivity (intent); break; default: break ;}} method 3 [java] package com. app; import android. app. activity; import android. content. intent; import android. OS. bundle; import android. view. view; import android. view. view. onClickListener; import android. widget. button; public class ThirdActivity extends Activity {private Button_OnClick mbutton = new Button_OnClick (); @ Override protected void onCreate (Bundle savedInstanceState) {// TODO Auto-generated method stub super. onCreate (savedInstanceState); setContentView (R. layout. activity_third); Button button = (Button) findViewById (R. id. button1); button. setOnClickListener (mbutton);} class Button_OnClick implements OnClickListener {@ Override public void onClick (View v) {// TODO Auto-generated method stub switch (v. getId () {case R. id. button1: Intent intent = new Intent (); intent. setClass (ThirdActivity. this, MainActivity. class); startActivity (intent); break; default: break ;}}}}