Android之Service学习篇二：Service启动方式之boundService

转于：

http://blog.csdn.net/wulianghuan/article/details/8600361

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上一篇中介绍了Service的第一种方式，startService，这一篇来讲解一下另一张方式 bindService。

当创建一个能提供绑定功能的服务时，我们必须提供一个IBinder对象，客户端能使用这个对象与服务进行交换。在Android中有三种定义方式：

1、扩展Binder类 (条件：服务和应用在同一个进程当中，是最常见的情况)

2、使用Messager

3、使用AIDL (Android Interface Defination Language)

Bound Services

A bound service is the server in a client-server interface. A bound service allows components (such as activities) to bind to the service, send requests, receive responses, and even perform interprocess communication (IPC). A bound service typically lives only while it serves another application component and does not run in the background indefinitely.

这里以扩展Binder类为例讲解如何创建Bound Services.

Binder

extends?Object
implements?IBinder

java.lang.Object
????	android.os.Binder

很明显，Binder实现了IBinder这接口。

通过扩展Binder类创建Bound Service的步骤如下：

a、在Service类中，创建一个Binder实例，包含客户端能调用的公共方法，返回当前服务对象;

b、在onBind()方法中返回Binder实例;

c、在客户端,从onServiceConnected方法中获得Binder实例。

工程目录结构：

运行界面：

源代码：

MainActivity.java:

[html]?view plaincopyprint??
package?com.service.activity;??
??
import?com.service.activity.BinderService.MyBinder;??
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.view.View;??
import?android.view.View.OnClickListener;??
import?android.widget.Button;??
??
public?class?MainActivity?extends?Activity?{??
????private?Button?btnStartService;??
????private?Button?btnstopService;??
????private?boolean?isConnected?=?false;??
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????public?void?onCreate(Bundle?savedInstanceState)?{??
????????super.onCreate(savedInstanceState);??
????????setContentView(R.layout.main);??
????????btnStartService?=?(Button)findViewById(R.id.btnStartService);??
????????btnStartService.setOnClickListener(listener);??
????????btnstopService?=?(Button)findViewById(R.id.btnStopService);??
????????btnstopService.setOnClickListener(listener);??
????}??
??????
????private?OnClickListener?listener?=?new?OnClickListener()?{??
??????????
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????????public?void?onClick(View?v)?{??
????????????switch?(v.getId())?{??
????????????case?R.id.btnStartService:??
????????????????funBindService();??
????????????????break;??
????????????case?R.id.btnStopService:??
????????????????funUnBindService();??
????????????????break;??
????????????default:??
????????????????break;??
????????????}??
????????}??
????????private?void?funBindService()?{??
????????????Intent?intent?=?new?Intent(MainActivity.this,?BinderService.class);??
????????????bindService(intent,?conn,?Context.BIND_AUTO_CREATE);??
????????}??
??
????????private?void?funUnBindService()?{??
????????????if(isConnected?==?true){??
????????????????unbindService(conn);??
????????????}??
????????}??
??????????
????};??
??????
????private?ServiceConnection?conn?=?new?ServiceConnection()?{??
??????????
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????????public?void?onServiceDisconnected(ComponentName?name)?{??
????????????isConnected?=?false;??
????????}??
????????//与Service连接时被回调??
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????????public?void?onServiceConnected(ComponentName?name,?IBinder?iBinder)?{??
????????????MyBinder?myBinder?=?(MyBinder)iBinder;??
????????????BinderService?service?=?myBinder.getService();??
????????????service.MyMethod();??
????????????isConnected?=?true;??
????????}??
????};??
}??

BinderService.java

[html]?view plaincopyprint??
package?com.service.activity;??
??
import?android.app.Service;??
import?android.content.Intent;??
import?android.os.Binder;??
import?android.os.IBinder;??
import?android.util.Log;??
??
public?class?BinderService?extends?Service{??
????private?static?final?String?TAG?=?"BinderService";??
????private?MyBinder?myBinder?=?new?MyBinder();??
????//内部类，扩展自Binder类??
????public?class?MyBinder?extends?Binder{??
????????public?BinderService?getService(){??
????????????return?BinderService.this;??
????????}??
????}??
????//复写onBind方法，并且返回IBinder的实现类??
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????public?IBinder?onBind(Intent?intent)?{??
????????Log.i(TAG,?"onBind");??
????????return?myBinder;??
????}??
??????
????public?void?MyMethod(){??
????????Log.i(TAG,?"MyMethod");??
????}??
??
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????public?boolean?onUnbind(Intent?intent)?{??
????????Log.i(TAG,?"onUnbind");??
????????return?super.onUnbind(intent);??
????}??
??????
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????public?void?onDestroy()?{??
????????Log.i(TAG,?"onDestroy");??
????????super.onDestroy();??
????}??
??????
}??

main.xml:

[html]?view plaincopyprint??
<?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:layout_width="wrap_content"??
????????android:layout_height="wrap_content"??
????????android:text="启动service"??
????????android:id="@+id/btnStartService"/>??
????<Button???
????????android:layout_width="wrap_content"??
????????android:layout_height="wrap_content"??
????????android:text="停止service"??
????????android:id="@+id/btnStopService"/>??
??
</LinearLayout>??

点击启动service,日志输出信息：

点击停止service,日志输出信息：

Android之Service学习篇2：Service启动方式之boundService

Bound Services

Binder