初识 Service（二） 演示： Activity 调用Service的接口

先看代码：

import com.gdp2852.demo.service.BackgroundService.MyServiceBinder;import android.app.Activity;import android.content.ComponentName;import android.content.Intent;import android.content.ServiceConnection;import android.os.Bundle;import android.os.IBinder;import android.util.Log;import android.view.View;public class Demo_ServiceActivity extends Activity {public final static String Tag = "Demo_Service";    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                findViewById(R.id.bindBtn).setOnClickListener(new View.OnClickListener() {public void onClick(View v) {bindService(new Intent(Demo_ServiceActivity.this,BackgroundService.class),srvConn,BIND_AUTO_CREATE);}});                findViewById(R.id.unbindBtn).setOnClickListener(new View.OnClickListener() {public void onClick(View v) {unbindService(srvConn);}});    }            ServiceConnection srvConn = new ServiceConnection() {            public void onServiceConnected(ComponentName name, IBinder service) {Log.d(Tag, "onServiceConnected "+name);MyServiceBinder binder = (MyServiceBinder) service;binder.doLog(" Demo_ServiceActivity_CONTENT");}        public void onServiceDisconnected(ComponentName name) {    //在unbind和stop service都没有调用此函数Log.d(Tag, "onServiceDisconnected:"+name);}};}

Service的代码：

import android.app.Notification;import android.app.NotificationManager;import android.app.PendingIntent;import android.app.Service;import android.content.Intent;import android.os.Binder;import android.os.IBinder;import android.util.Log;public class BackgroundService extends Service {private MyServiceBinder binder = new MyServiceBinder();private NotificationManager notificationMrg;public void onCreate() {super.onCreate();notificationMrg = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);displayNotificationMessage("starting Background Service");doInBackground();}private void doInBackground() {new Thread(new Runnable() {public void run() {//TODO do what you wanna to do}}).start();}public void onDestroy() {displayNotificationMessage("stopping Background Service");super.onDestroy();}private void displayNotificationMessage(String message) {Notification notification = new Notification(R.drawable.sina, message,System.currentTimeMillis());PendingIntent contentIntent = PendingIntent.getActivity(this, 0,new Intent(this, Demo_ServiceActivity.class), 0);notification.setLatestEventInfo(this, "Background Service", message,contentIntent);notificationMrg.notify(R.id.app_notification_id, notification);}public IBinder onBind(Intent intent) {return binder;}class MyServiceBinder extends Binder{void doLog(String logContent){Log.d(Demo_ServiceActivity.Tag, "invoke MyServiceBinder doLog:"+logContent);}}}

ServiceConnection srvConn = new ServiceConnection() {            public void onServiceConnected

在ServiceConnection连接的时会，可以从onServiceConnected（）中拿到IBinder引用，这样就可以从通过IBinder调用Service的方法了

另外，需注意：

1 如果onBinder返回的是null, 则不会调用onServiceConnected（）

2 unbindService()却不会调用onServiceDisconnected接口. unbindService只是告诉系统，你的APP已经跟这个service没什么关系了,

  系统有权回收这个Service。

工程代码下载： http://download.csdn.net/detail/gdp2852/3783686