Android Service full resolution (2)-bindService

Mainactivity is as follows:

Package cc. testservice2; import android. app. activity; import android. content. componentName; import android. content. intent; import android. content. serviceConnection; import android. OS. bundle; import android. OS. IBinder; import android. view. view; import android. view. view. onClickListener; import android. widget. button; import android. widget. textView;/*** Demo Description: * use the bindService () method to start the service * the local service described in this Demo, that is, the service and the visitor are in the same Process ** client summary: * core purpose of the client (MainActivity here): * Get the Binder object returned by the Service, then use this Binder object to call the related methods in the service ** detailed steps: * 1 Write A ServiceConnectionImpl class to implement the ServiceConnection interface * that is, private final class ServiceConnectionImpl implements ServiceConnection * 2 create a ServiceConnectionImpl class Object conn. then use Context to activate the service and establish a connection with the Service * that is, this. bindService (service, conn, this. BIND_AUTO_CREATE); * 3 overwrite the public void onServiceConnecte of the ServiceConnectionImpl class D (ComponentName name, IBinder service) * method. This is a callback Method !!!! After the client establishes a connection with the service, the public IBinder onBind (Intent intent) () method * of the server returns an IBinder object to the client. this IBinder object is the service * 4 in the * public void onServiceConnected (ComponentName, IBinder service) method. Use the IBinder object returned by the server to call the method in the service. ** note: * 1 The mServiceConnectionImpl object is used for binding and unbinding, and its class implements the ServiceConnection interface * 2 note that not only do you need to override the onCreate () of MainActivity to establish a connection with the service, and rewrite the onDestroy () method of the Activity! * So that the connection to the service is closed when the Activity exits. * 3. Why define an interface in this small application? * Because the service returns a Binder object to MainActivity, MainActivity receives this object. This object is an internal class object in the service. * In general, internal classes are private. Therefore, in MainActivity, it is impossible to add () An internal class object to receive this object * So an interface is defined here ---> to receive the Binder object using the interface. in this way, the business is abstracted as an interface. ** server Summary: * 1. The Custom Service ServiceSubclass inherits from the Service * 2. Write a custom internal class BinderSubclass to implement the business interface, and inherits from Binder * 3 to override the public IBinder onBind (Intent intent) method of the Service, and returns an IBinder object. * BinderSubclass class Object */public class MainActivity extends Activity {TextView mNumberTextView; TextView mResultTextView; Button mSearchButton; ServiceConnectionImpl callback; QueryInterface mBinder; public void onCreate (Bundle created) {super. onCreate (savedInstanceState); setContentView (R. layout. main); // The Binder object mServiceConnectionImpl = new ServiceConnectionImpl (); mNumberTextView = (TextView) findViewById (R. id. numberEditText); mResultTextView = (TextView) findViewById (R. id. resultTextView); mSearchButton = (Button) findViewById (R. id. searchButton); mSearchButton. setOnClickListener (new ButtonOnClickListener (); Intent intent = new Intent (this, ServiceSubclass. class); // The bindService (intent, mServiceConnectionImpl, this. BIND_AUTO_CREATE);} private class ButtonOnClickListener implements OnClickListener {public void onClick (View v) {String number = mNumberTextView. getText (). toString (); String result = mBinder. queryByNumber (Integer. valueOf (number); mResultTextView. setText (result) ;}}// when binding a service and unbinding a service private final class ServiceConnectionImpl implements ServiceConnection {// when binding a service, this method calls public void onServiceConnected (ComponentName, IBinder service) {mBinder = (QueryInterface) service;} // when the service is removed, this method calls public void onServiceDisconnected (ComponentName name) {mBinder = null ;}} // remove the connection from the service. protected void onDestroy () {unbindService (mServiceConnectionImpl); super. onDestroy ();}}

Servicesubclass:

Package CC. testservice2; import android. app. service; import android. content. intent; import android. OS. binder; import android. OS. ibinder;/*** server Summary: * 1. The Custom Service servicesubclass inherits from the Service * 2. Write a custom internal class bindersubclass to implement the business interface, and inherits from binder * 3 to override the public ibinder onbind (intent) method of the service, and returns an ibinder object. * bindersubclass Class Object */public class servicesubclass extends Service {private string [] names = new string [] { "Xiao Ming", "Xiao Wang", "Xiao Yang", "Xiao Li", "Xiao Qiang"}; bindersubclass mbindersubclass = new bindersubclass (); @ overridepublic ibinder onbind (intent) {return mbindersubclass;} // querybynumber is the Business Method in the interface. // In general, the service is abstracted as an interface and then implemented, for example, here. // Note: bindersubclass inherited from binder also implements the business interface private final class bindersubclass extends binder implements QueryInterface {Public String querybynumber (INT number) {return query (number );}} // Public String query (int I) {if (I> 0 & I <6) {return Names [I-1];} return "query error, enter ";}} again ";}}

QueryInterface:

Package cc. testservice2; // service interface public interface QueryInterface {public String queryByNumber (int number );}

Main. xml is as follows:

<? Xml version = "1.0" encoding = "UTF-8"?> <LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android" android: layout_width = "fill_parent" android: layout_height = "fill_parent" android: orientation = "vertical"> <TextView android: layout_width = "fill_parent" android: layout_height = "wrap_content" android: text = "enter a number ranging from 1 to 5"/> <EditText android: id = "@ + id/numberEditText" android: layout_width = "fill_parent" android: layout_height = "wrap_content"/> <Button android: id = "@ + id/searchButton" android: layout_width = "wrap_content" android: layout_height = "wrap_content" android: text = "query"/> <TextView android: id = "@ + id/resultTextView" android: layout_width = "fill_parent" android: layout_height = "wrap_content"/> </LinearLayout>