Android-three ways to implement listeners

First: In a class, define a class interface, and then give the definition of the class (the simplest and most intuitive)

 Public classTestextendsactivity{Button btn;  Public voidonCreate (Bundle savedinstancestate) {Super. OnCreate (savedinstancestate);    Setcontentview (R,layout.main); ///Add Listener to buttonMyonclicklistener listener=NewMyonclicklistener ();   Btn.setonclicklistener (listener); }    ///give the definition of the listener class    classMyonclicklistenerImplementsonclicklistener{@Override Public voidOnClick (View arg0) {toast.maketest......show (); }   }}

The second kind: using anonymous inner classes (the one you see most often, is actually writing the first type together)

 Public class extends Activity {Button btn;  Public void onCreate (Bundle savedinstancestate) {    super. OnCreate (savedinstancestate);    Setcontentview (r. layout.main);         // anonymous inner class notation    Btn.setonclicklistener (new  Onclicklistener () {        @Override         public  void  onclic (View v) {            Toast. maketest....show ();         }}    );}}

Third: Use more simplification to implement the listener interface directly on the class

 Public classTestextendsActivityImplementsOnclicklistener{button btn; Public voidonCreate (Bundle savedinstancestate) {Super. OnCreate (savedinstancestate);        Setcontentview (r. Layout.main); Btn.setonclicklistener ( This);} //////The direct override of the OnClick method can@Override Public voidOnClick (View v) {Toast. Maketext (...).    Show (); }}

Android-three ways to implement listeners