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