Android Service (ii)

The way we started the service in the previous article was:

StartService ()

       New Intent ("Android.startservice"); // Differentiate service Types               Bundle Bundle  new  bundle ();        Bundle.putint ("Op", op);        Intent.putextras (bundle);        StartService (intent);         // Intent.setclass can also be used here (This,startmusicservice.class);   Such intent=new Intent ();

Bindservice

        New Intent ("Android.bindservice");         // can also: Intent Intent = new Intent (mainactivity.this,bindmusicservice.class);         // Context.bind_auto_create: The service is created automatically as long as the activity and service are bound        Bindservice (Intent, SC, context.bind_auto_create);

Are methods that directly start the service. We can also start the Service (service) indirectly through activity and broadcast (broadcast), and this article will learn how to start the services by broadcasting broadcast.

Perhaps you would say that you can start with activity, why use the radio?

For example, the playback, pause, and stop of your music player are usually placed in a service. We had a phone call when we listened to the song, or we pulled out the headphones, and we asked to pause the music. How is this effect done? Call and unplug the headset the system sends a system message to the program. We can build a broadcastreceiver subclass, receive the message after registering the broadcast receiver, and then start the service in OnReceive (pause processing). If we start the service directly, we will not be able to start the service for the message (must be broadcast).

General: The Service is initiated indirectly by means of a broadcast: the processing is done for the system message, and this processing is in service.

Example:

Activity_main.xml

<?XML version= "1.0" encoding= "Utf-8"?><LinearLayoutxmlns:android= "Http://schemas.android.com/apk/res/android"android:orientation= "vertical"Android:layout_width= "Fill_parent"Android:layout_height= "Fill_parent">    <ButtonAndroid:id= "@+id/send"Android:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"Android:text= "Start service via broadcast" /></LinearLayout>

Mainactivity.java

 PackageCom.genwoxue.broadcastservice;ImportAndroid.os.Bundle;ImportAndroid.view.View;ImportAndroid.view.View.OnClickListener;ImportAndroid.widget.Button;Importandroid.app.Activity;Importandroid.content.Intent;ImportAndroid.content.IntentFilter; Public classMainactivityextendsActivity {PrivateBroadcastreceiverutil util=NULL; PrivateButton btnsend=NULL; @Overrideprotected voidonCreate (Bundle savedinstancestate) {Super. OnCreate (savedinstancestate);                Setcontentview (R.layout.activity_main); Btnsend= (Button)Super. Findviewbyid (R.id.send); Btnsend.setonclicklistener (NewOnclicklistener () {@Override Public voidOnClick (View v) {//Send broadcast: Its action is "Com.genwoxue.action.ABOUTSERVICE"Intent intent=NewIntent ("Com.genwoxue.action.ABOUTSERVICE"); Mainactivity. This. Sendbroadcast (Intent); //instantiate a broadcast filter (only filter its action to "Com.genwoxue.action.ABOUTSERVICE")Intentfilter filter=NewIntentfilter ("Com.genwoxue.action.ABOUTSERVICE"); //instantiate a broadcast sink (receiver)Util=NewBroadcastreceiverutil (); //Register Broadcastreceiver: parameter is receiver and filterMainactivity. This. Registerreceiver (util, filter);    }        }); } @Overrideprotected voidOnStop () {//Stop Broadcasting        Super. Unregisterreceiver (util); Super. OnStop (); //Stop ServiceIntent intent=NewIntent (mainactivity. This, Serviceutil.class); Mainactivity. This. StopService (Intent); }}

View Code

Broadcastreceiverutil.java

 PackageCom.genwoxue.broadcastservice;ImportAndroid.content.BroadcastReceiver;ImportAndroid.content.Context;Importandroid.content.Intent; Public classBroadcastreceiverutilextendsbroadcastreceiver{@Override Public voidonreceive (Context context,intent Intent) {//The Broadcast receiver (receiver) determines that the action is "Com.genwoxue.action.ABOUTSERVICE" and starts the service        if("Com.genwoxue.action.ABOUTSERVICE". Equals (Intent.getaction ())) {Context.startservice (NewIntent (Context,serviceutil.class)); }            }}

View Code

Serviceutil.java

 PackageCom.genwoxue.broadcastservice;ImportAndroid.app.Service;Importandroid.content.Intent;ImportAndroid.os.IBinder;ImportAndroid.util.Log; Public classServiceutilextendsservice{Private Static FinalString tag= "Aboutservice"; @Override Publicibinder onbind (Intent Intent) {return NULL; } @Override Public voidonCreate () {log.i (TAG,"Service: OnCreate ()"); }        //Start@Override Public intOnstartcommand (Intent Intent,intFlagsintStartid) {log.i (TAG,"Service startup: OnStart () =>intent" +intent+ ", startid=" +Startid); returnService.start_continuation_mask; } @Override Public voidOnDestroy () {log.i (TAG,"Service: OnDestroy ()"); }}

View Code

Register in Androidmanifest.xml:

　　<android:name= "Com.genwoxue.broadcastservice.ServiceUtil"/>

Operation Result:

Reference: http://blog.csdn.net/jianghuiquan/article/details/8641152#

Android Service (ii)