Learn Android<service services from scratch. 43 .>

Services is an important component in the development of Android systems. If some of the operations that some programs require now are time-consuming, you can define them in the service so that you can run the program in the background (or run in the form of a non-display interface), which is: Services It's actually the equivalent of a non-graphical interface. Activity program, and the service can be used when the user wants to perform certain operations that require cross-process access. Service is an operating component without UI interface, the main function is to provide some necessary support for the activity program, such as: MP3 player software in the mobile phone, the components can still run when they return to the desktop, in fact, these are the functions of the service, At development time, the user only needs to inherit from the Android.app.Service class to complete the service program development, in the service also has its own life cycle method.
Next, use an example to illustrate the life cycle of the service.

<relativelayout xmlns:android= "http://schemas.android.com/apk/res/android" xmlns:tools= "http// Schemas.android.com/tools "android:layout_width=" match_parent "android:layout_height=" Match_parent "Android:paddi ngbottom= "@dimen/activity_vertical_margin" android:paddingleft= "@dimen/activity_horizontal_margin" Android: paddingright= "@dimen/activity_horizontal_margin" android:paddingtop= "@dimen/activity_vertical_margin" tools: Context= ". Mainactivity "> <button android:id=" @+id/button1 "android:layout_width=" Wrap_content "Androi        d:layout_height= "Wrap_content" android:layout_alignparenttop= "true" android:layout_centerhorizontal= "true"         android:layout_margintop= "90DP" android:text= "open service"/> <button android:id= "@+id/button2" Android:layout_width= "Wrap_content" android:layout_height= "wrap_content" android:layout_alignleft= "@ +id/button1 "android:layout_below=" @+id/buttoN1 "android:layout_margintop=" 100DP "android:text=" Close Service "/></relativelayout> 

Sevice

Package Com.example.service2;import Android.app.service;import Android.content.intent;import android.os.IBinder; Import Android.util.log;public class MyService extends Service {@Overridepublic ibinder onbind (Intent Intent) {//TODO Aut O-generated method Stubreturn null;} @Overridepublic void OnCreate () {//TODO auto-generated method Stubsuper.oncreate (); LOG.I ("Log", "OnCreate");} @Overridepublic void OnDestroy () {//TODO auto-generated method Stubsuper.ondestroy (); LOG.I ("Log", "OnDestroy");} @Overridepublic int Onstartcommand (Intent Intent, int flags, int startid) {//TODO auto-generated method stublog.i ("Log", "Onstartcommand"); return Super.onstartcommand (Intent, flags, Startid);}}

Main class

Package Com.example.service2;import Android.os.bundle;import Android.app.activity;import android.content.Intent; Import Android.view.menu;import Android.view.view;import Android.widget.button;public class MainActivity extends Activity {Private Button button1, button2; @Overrideprotected void OnCreate (Bundle savedinstancestate) {super.oncreate ( Savedinstancestate); Setcontentview (r.layout.activity_main); button1 = (Button) This.findviewbyid (R.id.button1); Button2 = (Button) This.findviewbyid (R.id.button2); Button1.setonclicklistener (new View.onclicklistener () {@ overridepublic void OnClick (View v) {//TODO auto-generated method stubintent intent=new Intent (Mainactivity.this, MyServ Ice.class); StartService (intent);}); Button2.setonclicklistener (New View.onclicklistener () {@Overridepublic void OnClick (View v) {//TODO auto-generated Method Stubintent Intent=new Intent (mainactivity.this, Myservice.class); StopService (intent);}});}}

To bind a service to activity

<relativelayout xmlns:android= "http://schemas.android.com/apk/res/android" xmlns:tools= "http// Schemas.android.com/tools "android:layout_width=" match_parent "android:layout_height=" Match_parent "Android:paddi ngbottom= "@dimen/activity_vertical_margin" android:paddingleft= "@dimen/activity_horizontal_margin" Android: paddingright= "@dimen/activity_horizontal_margin" android:paddingtop= "@dimen/activity_vertical_margin" tools: Context= ". Mainactivity "> <button android:id=" @+id/button1 "android:layout_width=" Wrap_content "Androi        d:layout_height= "Wrap_content" android:layout_alignleft= "@+id/button2" android:layout_alignparenttop= "true" android:layout_margintop= "22DP" android:text= "open service"/> <button android:id= "@+id/button2 "Android:layout_width=" wrap_content "android:layout_height=" Wrap_content "android:layout_alignright= "@+id/button4" android:layout_below= "@+id/butTon4 "android:layout_margintop=" 32DP "android:text=" close service "/> <button android:id=" @+id/b Utton3 "android:layout_width=" wrap_content "android:layout_height=" Wrap_content "android:layout_align left= "@+id/button1" android:layout_below= "@+id/button1" android:layout_margintop= "32DP" android:text= "Bind service"/> <button android:id= "@+id/button4" android:layout_width= "Wrap_content" Android        : layout_height= "Wrap_content" android:layout_centerhorizontal= "true" android:layout_centervertical= "true" android:text= "Unbind"/></relativelayout>

Service

Package Com.example.service1;import Android.app.service;import Android.content.intent;import android.os.Binder; Import Android.os.ibinder;public class MyService extends Service {private IBinder Mybinder = new Binder () {@Override//serv Ice defines the method public String Getinterfacedescriptor () {System.out.println ("***mybinder"); return "MyService Class.";}}; @Overridepublic ibinder onbind (Intent Intent) {System.out.println ("* * * Service Onbind ()"); return this.mybinder;// No processing is done here temporarily} @Overridepublic void Onrebind (Intent Intent) {//Rebind System.out.println ("* * * Service Onrebind ()"); Super.onrebind (intent);} @Overridepublic boolean onunbind (Intent Intent) {//unbound System.out.println ("* * * Service Onunbind ()"); return Super.onunbind (intent);} @Overridepublic void OnCreate () {//create servicesuper.oncreate (); SYSTEM.OUT.PRINTLN ("* * * Service onCreate ()");} @Overridepublic void OnDestroy () {//Destroy Servicesuper.ondestroy (); SYSTEM.OUT.PRINTLN ("* * * Service OnDestroy ()");} @Overridepublic int Onstartcommand (Intent Intent, intFlags, int Startid)//Execute SERVICE{SYSTEM.OUT.PRINTLN ("* * * Service onstartcommand"); return Service.start_continuation_ MASK; Continue execution}}

Mainactivity

Package Com.example.service1;import Android.app.activity;import Android.content.componentname;import Android.content.context;import Android.content.intent;import Android.content.serviceconnection;import Android.os.bundle;import Android.os.ibinder;import Android.os.remoteexception;import Android.view.View;import Android.widget.button;public class Mainactivity extends Activity {private Button button1,button2,button3,button4;// Bind service and activity to private serviceconnection serviceconnection = new Serviceconnection () {@Overridepublic void onserviceconnected (componentname name, IBinder service) {try {System.out.println ("# # # Service Connect Success. Service = "+ Service.getinterfacedescriptor ());} catch (RemoteException e) {}} @Overridepublic void onservicedisconnected (componentname name) {System.out.println ("# # #    Service Connect Failure. ");};        @Override protected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate); Setcontentview (r.layout.activity_Main);        button1= (Button) This.findviewbyid (R.id.button1);        Button2= (Button) This.findviewbyid (R.id.button2);        button3= (Button) This.findviewbyid (R.id.button3); button4= (Button) This.findviewbyid (R.ID.BUTTON4);//Start Service monitoring Button1.setonclicklistener (new View.onclicklisten ER () {@Overridepublic void OnClick (View v) {//TODO auto-generated method StubMainActivity.this.startService (New Intent ( Mainactivity.this, Myservice.class)); OnStart ();}); /Shutdown Service Listener Button2.setonclicklistener (new View.onclicklistener () {@Overridepublic void OnClick (View v) {//TODO Au         To-generated method StubMainActivity.this.stopService (New Intent (Mainactivity.this, Myservice.class)); OnStop ();}}); Button3.setonclicklistener (New View.onclicklistener () {@Overridepublic void OnClick (View v) {//TODO auto-generated met  Hod StubMainActivity.this.bindService (New Intent (Mainactivity.this, Myservice.class), Mainactivity.this.serviceconnection,context.bind_auto_create);}); Button4.setonclicklistener (New View.onclicklistener () {@Overridepublic void OnClick (View v) {//TODO auto-generated    Method StubMainActivity.this.unbindService (Serviceconnection);}}); }    }

Open



Binding


Unbind


Destroying service






Using the service to get other operations on the system

1	public static final String Clipboard_service	Constant	Clipboard Service
2	public static final String Window_service	Constant	Window Services
3	public static final String Alarm_service	Constant	Alarm Service
4	public static final String Audio_service	Constant	Audio Services
5	public static final String Notification_service	Constant	Notification Service
6	public static final String Search_service	Constant	Search Service
7	public static final String Power_service	Constant	Power Management Services
8	public static final String Wifi_service	Constant	WiFi Service
9	public static final String Activity_service	Constant	Running the program service

Today, we will simply use two examples to illustrate
Using the service to get the Clipboard service

<relativelayout xmlns:android= "http://schemas.android.com/apk/res/android"    xmlns:tools= "http// Schemas.android.com/tools "    android:layout_width=" match_parent "    android:layout_height=" Match_parent "    android:paddingbottom= "@dimen/activity_vertical_margin"    android:paddingleft= "@dimen/activity_ Horizontal_margin "    android:paddingright=" @dimen/activity_horizontal_margin "    android:paddingtop=" @dimen /activity_vertical_margin "    tools:context=". Mainactivity ">    <edittext        android:id=" @+id/edittext1 "        android:layout_width=" Wrap_content "        android:layout_height= "wrap_content"        android:layout_alignparenttop= "true"        android:layout_ Centerhorizontal= "true"        android:layout_margintop= "41DP"        android:ems= "ten" >        <requestfocus/ >    </EditText></RelativeLayout><strong></strong>

Package Com.example.service3;import Android.os.bundle;import Android.app.activity;import Android.content.clipboardmanager;import Android.view.menu;public class Mainactivity extends Activity {    @Override    protected void OnCreate (Bundle savedinstancestate) {        super.oncreate (savedinstancestate);        Setcontentview (R.layout.activity_main);//        Get Clipboardmanager object Clipboardmanager clipboardmanager= ( Clipboardmanager) Getsystemservice (clipboard_service);//Set Text Clipboardmanager.settext ("Wind snow is not Young");}    }

using the service to operate the phone wifi

<?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 " ><textviewandroid:id= "@+id/msg" android:layout_width= "fill_parent" android:layout_height= "wrap_content"/ ><buttonandroid:id= "@+id/open" android:layout_width= "fill_parent" android:layout_height= "Wrap_content" android:text= "Open WiFi"/><buttonandroid:id= "@+id/close" android:layout_width= "Fill_parent" Android:layout_ height= "Wrap_content" android:text= "Off WiFi"/><buttonandroid:id= "@+id/check" android:layout_width= "Fill_ Parent "android:layout_height=" wrap_content "android:text=" Check wifi status "/></linearlayout>

Package Com.example.service5;import Android.app.activity;import Android.content.context;import Android.net.wifi.wifimanager;import Android.os.bundle;import Android.view.view;import Android.view.view.onclicklistener;import Android.widget.button;import Android.widget.textview;public Class  Mainactivity extends Activity {private button open = null;//button component Private button close = null;//button component Private button check = null;//button Component Private TextView msg = null;//text component private Wifimanager Wifimanager = null;//wifi management @overridepublic void Oncre Ate (Bundle savedinstancestate) {super.oncreate (savedinstancestate); Super.setcontentview (R.layout.activity_main) ;//Configuration layout Manager This.open = (button) Super.findviewbyid (r.id.open);//Get Component This.close = (Button) Super.findviewbyid ( R.id.close);//Get Component This.check = (Button) Super.findviewbyid (R.id.check);//Get Component this.msg = (TextView) Super.findviewbyid (r.id.msg);//Get Component This.wifimanager = (Wifimanager) super.getsystemservice (Context.WIFI_SERVICE) ;//Get wife service This.open.setOnClickLIstener (New Onclicklistener () {@Overridepublic void OnClick (view view) {MainActivity.this.wifiManager.setWifiEnabled (true); Enable WifiMainActivity.this.msg.setText ("Open WiFi, Status:" + MainActivity.this.wifiManager.getWifiState ());//Set Text}}); This.close.setOnClickListener (New Onclicklistener () {@Overridepublic void OnClick (view view) { MainActivity.this.wifiManager.setWifiEnabled (FALSE); Turn off WIFIMainActivity.this.msg.setText ("Turn off WiFi, status:" + MainActivity.this.wifiManager.getWifiState ());//Set Text}}); This.check.setOnClickListener (New Onclicklistener () {@Overridepublic void OnClick (view view) { MainActivity.this.msg.setText ("Check WiFi, Status:" + MainActivity.this.wifiManager.getWifiState ());//Set Text}});}}

Of course, you can refer to the API below to get other services and configure the corresponding, the others are no longer one by one description.

next section forecast: Notification notice

Learn Android<service services from scratch. 43 .>