Four types of onclick events in Android

Package Com.example.dailphone;import Android.support.v7.app.actionbaractivity;import Android.support.v7.app.actionbar;import Android.support.v4.app.fragment;import Android.text.TextUtils;import Android.content.intent;import Android.net.uri;import Android.os.bundle;import Android.view.LayoutInflater;import Android.view.menu;import Android.view.menuitem;import Android.view.view;import Android.view.View.OnClickListener; Import Android.view.viewgroup;import Android.widget.button;import Android.widget.edittext;import Android.widget.toast;import Android.os.build;public class Mainactivity extends Actionbaractivity implements onclicklistener{/** Call button */private button bt_dail;/** text box when entering a phone */private EditText et_number; @Overrideprotected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate); Setcontentview (R.layout.activity_main);    /Get button Bt_dail = (button) Findviewbyid (R.id.bt_dail);    Get text Box Et_number = (EditText) MainActivity.this.findViewById (R.id.et_number);Add event//1 to the button.    Create an internal class definition click event//bt_dail.setonclicklistener (New Mylisenner ()); 2. New an anonymous inner class defines the Click event/* Bt_dail.setonclicklistener (New Onclicklistener () {@Overridepublic void OnClick (View v) {Callphone ( );}}); *///3.           Mainactivity implement Onclicklistener interface, common method, through the view of id+switch implementation of multiple events//bt_dail.setonclicklistener (this); }//4. In the layout of the file surface binding a click on the method/* * <button android:onclick= "dailbuttononclicked" android:id= "@+id/bt_dail" and roid:layout_margintop= "40DP" android:layout_marginleft= "200DP" android:layout_width= "Wrap_content" an  droid:layout_height= "Wrap_content" android:text= "@string/dail"/> */public void dailbuttononclicked (View v) {Callphone ();} Private class Mylisenner implements Onclicklistener {@Overridepublic void OnClick (View v) {callphone ();}} @Overridepublic void OnClick (View v) {switch (V.getid ()) {case r.id.bt_dail:callphone (); break;default:break;}} Call private void Callphone () {String number = Et_nUmber.gettext (). toString (). Trim ();//The empty operation gives the "spin" hint if (textutils.isempty (number)) {Toast toast = Toast.maketext ( Mainactivity.this, "Number cannot be empty", toast.length_short); Toast.show (); return;} intention, want to do one thing (tea) Intent Intent = new Intent (); intent.setaction (Intent.action_call); Intent.setdata (Uri.parse ("Tel:" + number); StartActivity (intent);}}