Service中有四个重要函数：

    public IBinder onBind(Intent arg0)；    //必须实现，返回接口给Servicepublic void onCreate()；                //Service创建时调用public void onStart(Intent intent,int startId)；//通过startService（）会调用public void onDestroy()；                //销毁时StopService()调用

通过StartActivity（）函数启动Service，当第一次调用时会分别调用onCreate()和onStart在()；

之后只会调用onStart()；

通过函数StopService()结束Service，会调用onDestroy()；

调用BindService()：当Service未创建时调用onCreate()和onBind()；当创建了只调用onBind()；

使用函数bindService()和函数unbindService()可以绑定和解除绑定

对已经绑定的Service调用bindService()无效，即多次调用bindService()和调用一次bindService()一样。 unbindService()只能使用一次，即对于一个绑定的Service，只能调用一次unbindService()，多次调用会产生错误

该函数原型为：

bindService(Intent,ServiceConnection,BIND_AUTO_CREATE);

ServiceConnection是一个服务连接类，必须实现以下两个函数：

public void onServiceConnected(ComponentName arg0, IBinder arg1)//连接成功时调用
public void onServiceDisconnected(ComponentName arg0)        //连接失败时调用

示例如下：

private ServiceConnection conn=new ServiceConnection() {@Overridepublic void onServiceConnected(ComponentName arg0, IBinder arg1) {// TODO Auto-generated method stubToast.makeText(MainActivity.this, "success", Toast.LENGTH_LONG).show();Log.i("SERVICE","success");}@Overridepublic void onServiceDisconnected(ComponentName arg0) {// TODO Auto-generated method stubToast.makeText(MainActivity.this, "errer", Toast.LENGTH_LONG);Log.i("SERVICE","errer");}

Service实例：

MainActivity.java:

private ServiceConnection conn=new ServiceConnection() {@Overridepublic void onServiceConnected(ComponentName arg0, IBinder arg1) {// TODO Auto-generated method stubToast.makeText(MainActivity.this, "success", Toast.LENGTH_LONG).show();Log.i("SERVICE","success");}@Overridepublic void onServiceDisconnected(ComponentName arg0) {// TODO Auto-generated method stubToast.makeText(MainActivity.this, "errer", Toast.LENGTH_LONG);Log.i("SERVICE","errer");}
};

protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);Button button1=(Button)this.findViewById(R.id.btn1);Button button2=(Button)this.findViewById(R.id.btn3);Button button3=(Button)this.findViewById(R.id.btn4);Button button4=(Button)this.findViewById(R.id.btn5);button1.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View arg0) {// TODO Auto-generated method stubstartService(new Intent(MainActivity.this,NewService.class));}});button2.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View arg0) {// TODO Auto-generated method stubstopService(new Intent(MainActivity.this,NewService.class));}});button3.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View arg0) {// TODO Auto-generated method stubbindService(new Intent(MainActivity.this,NewService.class),conn,BIND_AUTO_CREATE);}});button4.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View arg0) {// TODO Auto-generated method stubunbindService(conn);}});
｝

NewService.java:

public class NewService extends Service {@Overridepublic IBinder onBind(Intent arg0) {// TODO Auto-generated method stubToast.makeText(NewService.this, "onBind", Toast.LENGTH_LONG).show();Log.i("SERVICE","onbind");return null;}public void onCreate() {super.onCreate();Log.i("SERVICE","oncreat");Toast.makeText(NewService.this, "onCreat", Toast.LENGTH_LONG).show();}public void onStart(Intent intent,int startId) {Log.i("SERVICE","onstart");Toast.makeText(NewService.this, "onStart", Toast.LENGTH_LONG).show();}public void onDestroy() {Log.i("SERVICE","ondestory");Toast.makeText(NewService.this, "onDestory", Toast.LENGTH_LONG).show();}
}

Activity.xml

<?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" ><Button android:id="@+id/btn1" android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="start"/><Button android:id="@+id/btn3" android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="stop"/><Button android:id="@+id/btn4" android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="bind"/><Button android:id="@+id/btn5" android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="unbind"/>
</LinearLayout>

AndroidManifest.xml增加：

 <service android:name="com.example.new1.NewService"/>