from:
http://blog.csdn.net/pugongying1988/article/details/7239124
1. register a service in manifest file . A stupid mistake that takes me one hour is that , the Four Big Parts(Activity, ContentProvider , Service , BroadcastReceiver ) must be registered INSIDE the APPLICATION !
Only the permissions must be writen outside the application label , better to be written before the application label .
2. set an intent filter for the service .
<service android:enabled="true"
android:name="MusicService">
<intent-filter>
<action android:name="com.service_test.MusicService"/>
</intent-filter>
</service>
3. create a CustomService extends Service. Override the onCreate(), onDestroy() , on StartCommand() .
4. use .startService(Intent intent) to start the Service . It will run in the system background or use the
.stopService(Intent intent) to stop it;
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.service_test"
android:versionCode="1"
android:versionName="1.0">
<application android:label="@string/app_name" >
<activity android:name="ServiceTest"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:enabled="true"
android:name="MusicService">
<intent-filter>
<action android:name="com.service_test.MusicService"/>
</intent-filter>
</service>
</application>
</manifest>
package com.service_test;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout;
public class ServiceTest extends Activity
{
private Button playBtn;
private Button stopBtn;
private Button pauseBtn;
private Button exitBtn;
private Button closeBtn;
public static final int ID_PLAY=1;
public static final int ID_STOP=2;
public static final int ID_PAUSE=3;
public static final int ID_EXIT=4;
public static final int ID_CLOSE=5;
private LinearLayout ll;
private LinearLayout.LayoutParams params;
private OnClickListener clickListener=new OnClickListener(){
public void onClick(View v) {
// throw new UnsupportedOperationException("Not supported yet.");
int op=-1;
Intent intent=new Intent();
intent.setAction("com.service_test.MusicService");
switch(v.getId()){
case ServiceTest.ID_PLAY:
Log.i("l","play music");
op=ServiceTest.ID_PLAY;
break;
case ServiceTest.ID_STOP:
Log.i("l","stop music");
op=ServiceTest.ID_STOP;
break;
case ServiceTest.ID_PAUSE:
Log.i("l","pause music");
op=ServiceTest.ID_PAUSE;
break;
case ServiceTest.ID_EXIT:
Log.i("l","exit");
// op=ServiceTest.ID_EXIT;
ServiceTest.this.finish();
stopService(intent);
break;
case ServiceTest.ID_CLOSE:
Log.i("l","close");
// op=ServiceTest.ID_CLOSE;
ServiceTest.this.finish();
break;
}//end switch
Bundle bundle=new Bundle();
bundle.putInt("op",op);
intent.putExtras(bundle);
ServiceTest.this.startService(intent);
Log.i("l","sendout op:"+op);
// sendBroadcast(intent);
}
};
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
params=new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.FILL_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
ll=new LinearLayout(this);
ll.setOrientation(LinearLayout.VERTICAL);
playBtn=new Button(this);
playBtn.setId(ServiceTest.ID_PLAY);
playBtn.setText("play");
ll.addView(playBtn, params);
stopBtn=new Button(this);
stopBtn.setId(ServiceTest.ID_STOP);
stopBtn.setText("stop");
ll.addView(stopBtn,params);
pauseBtn=new Button(this);
pauseBtn.setId(ServiceTest.ID_PAUSE);
pauseBtn.setText("pause");
ll.addView(pauseBtn,params);
exitBtn=new Button(this);
exitBtn.setId(ServiceTest.ID_EXIT);
exitBtn.setText("exit");
ll.addView(exitBtn,params);
closeBtn=new Button(this);
closeBtn.setId(ServiceTest.ID_CLOSE);
closeBtn.setText("close");
ll.addView(closeBtn);
setContentView(ll);
playBtn.setOnClickListener(clickListener);
stopBtn.setOnClickListener(clickListener);
pauseBtn.setOnClickListener(clickListener);
exitBtn.setOnClickListener(clickListener);
closeBtn.setOnClickListener(clickListener);
}
}
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package com.service_test;
import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.IBinder;
import android.util.Log;
/**
*
* @author Administrator
*/
public class MusicService extends Service{
private static final String TAG="MusicService";
private MediaPlayer mediaPlayer;
@Override
public IBinder onBind(Intent arg0) {
// throw new UnsupportedOperationException("Not supported yet.");
return null;
}
@Override
public void onCreate() {
super.onCreate();
Log.i("l","onCreate");
if(mediaPlayer==null){
mediaPlayer=MediaPlayer.create(this, R.raw.nine_crimes);
mediaPlayer.setLooping(false);
}
}
@Override
public void onDestroy() {
Log.i("l","onDestroy");
if(mediaPlayer!=null){
mediaPlayer.stop();
mediaPlayer.release();
}
super.onDestroy();
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.i("l","onStartCommand");
if(intent!=null){
Bundle bundle=intent.getExtras();
if(bundle!=null){
int op=bundle.getInt("op");
switch(op){
case ServiceTest.ID_PLAY:
play();
break;
case ServiceTest.ID_STOP:
stop();
break;
case ServiceTest.ID_PAUSE:
pause();
break;
default:
break;
}
}
}
return super.onStartCommand(intent, flags, startId);
}
private void play(){
if(!mediaPlayer.isPlaying()){
mediaPlayer.start();
}
}
private void stop(){
if(mediaPlayer!=null){
mediaPlayer.stop();
try{
//after use .stop() function , must use .prepare() function before .start() again;
mediaPlayer.prepare();
}
catch(Exception ex){
Log.e("l","music stop exception:"+ex);
}
}
}
private void pause(){
if(mediaPlayer!=null && mediaPlayer.isPlaying()){
mediaPlayer.pause();
}
}
}
from the website :
http://blog.csdn.net/pugongying1988/article/details/7239124
there is another method , which is to bind the service to the activity :
public class PlayBindMusic extendsActivityimplementsOnClickListener {
privatestaticfinal String TAG = "PlayBindMusic";
privateButton playBtn;
privateButton stopBtn;
privateButton pauseBtn;
privateButton exitBtn;
privateBindMusicService musicService;
@Override
publicvoidonClick(View v) {
switch(v.getId()) {
caseR.id.play:
Log.d(TAG,"onClick: binding srvice");
musicService.play();
break;
caseR.id.stop:
Log.d(TAG,"onClick: stoping srvice");
if(musicService !=null){
musicService.stop();
}
break;
caseR.id.pause:
Log.d(TAG,"onClick: pausing srvice");
if(musicService !=null){
musicService.pause();
}
break;
caseR.id.exit:
Log.d(TAG,"onClick: exit");
this.finish();
break;
}
}
privatevoidconnection(){
Log.d(TAG,"connecting.....");
Intent intent =newIntent("org.allin.android.bindService");
bindService(intent, sc, Context.BIND_AUTO_CREATE);
}
privateServiceConnection sc =newServiceConnection() {
@Override
publicvoidonServiceDisconnected(ComponentName name) {
musicService =null;
Log.d(TAG,"in onServiceDisconnected");
}
@Override
publicvoidonServiceConnected(ComponentName name, IBinder service) {
musicService = ((BindMusicService.MyBinder)(service)).getService();
if(musicService !=null){
musicService.play();
}
Log.d(TAG,"in onServiceConnected");
}
};
}
/**
* @author allin.dev
*http://allin.cnblogs.com/
*/
public class BindMusicService extendsService {
privatestaticfinal String TAG = "MyService";
privateMediaPlayer mediaPlayer;
privatefinalIBinder binder =newMyBinder();
publicclassMyBinder extendsBinder {
BindMusicService getService() {
returnBindMusicService.this;
}
}
/*
* (non-Javadoc)
*
* @see android.app.Service#onBind(android.content.Intent)
*/
@Override
publicIBinder onBind(Intent intent) {
Log.d(TAG,"onBind");
play();
returnbinder;
}
@Override
publicvoidonCreate() {
super.onCreate();
Log.d(TAG,"onCreate");
Toast.makeText(this,"show media player", Toast.LENGTH_SHORT).show();
}
@Override
publicvoidonDestroy() {
super.onDestroy();
Log.d(TAG,"onDestroy");
Toast.makeText(this,"stop media player", Toast.LENGTH_SHORT);
if(mediaPlayer !=null){
mediaPlayer.stop();
mediaPlayer.release();
}
}
publicvoidplay() {
if(mediaPlayer ==null) {
mediaPlayer = MediaPlayer.create(this, R.raw.tmp);
mediaPlayer.setLooping(false);
}
if(!mediaPlayer.isPlaying()) {
mediaPlayer.start();
}
}
publicvoidpause() {
if(mediaPlayer !=null&& mediaPlayer.isPlaying()) {
mediaPlayer.pause();
}
}
publicvoidstop() {
if(mediaPlayer !=null) {
mediaPlayer.stop();
try{
// 在调用stop后如果需要再次通过start进行播放,需要之前调用prepare函数
mediaPlayer.prepare();
}catch(IOException ex) {
ex.printStackTrace();
}
}
}
}