Android activity and service communication

1. When acitivity and service are in the same application and process, they are implemented by inheriting the binder class.

WhenActivityBind toServiceIt is responsible for maintenanceServiceInstance reference, allowing youServiceCall some methods.For example, if you have a background service for playing background music, you can use this method for communication.

CodeAs follows:

 /**  * ********************* Service Code *************** ************************  */ 
 Public   Class LocalServiceExtends Service {
 Private   Final Ibinder binder = New Localbinder ();

 Public   Class Localbinder Extends Binder {
LocalService getservice (){
 Return LocalService. This ;
}
}

Public Ibinder onbind (intent ){
 Return Binder;
}
}

 /**  *********** *************************  */ 
 Public   Class Bindingactivity Extends Activity {
LocalService;

 Private Serviceconnection mconnection = New Serviceconnection (){
 Public   Void Onserviceconnected (componentname classname, ibinder localbinder ){
LocalService = (localbinder) localbinder. getservice ();
}
 Public   Void Onservicedisconnected (componentname arg0 ){
LocalService = Null ;
}
};

Protected   Void Onstart (){
 Super . Onstart ();

Intent intent = New Intent ( This , LocalService. Class );
Bindservice (intent, mconnection, context. bind_auto_create );
}

 Protected   Void Onstop (){
 Super . Onstop ();
Unbindservice (mconnection );
}

 Public   Void Printrandomnumber {
 Int Num = LocalService. getrandomnumber ();
System. Out. println (Num );
}
}

Code explanation:

UseContext. Bindservice () will start the service:
Context. Bindservice ()-> oncreate ()-> onbind ()-> Service Running
Onunbind ()->Ondestroy ()-> service stop

activity can be bound to service interface onbind (). service and activity connections can be used serviceconnection , A new serviceconnection , rewrite onserviceconnected and onservicedisconnected method. bind the instance, call the bindservice method, input a service > intent (explicit or implicit) and a serviceconnection instance. once a connection is established, you can use the onbind () interface of service () Get servicebinder Instance to obtain Service Instance reference. Once Service Object found, You can get its public methods and attributes. However, this method must be in the same process and application.