Service使用方式
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使用Service的场合：
1.一个或多个Activity需要向同一应用中的Service发出执行某一操作的命令。
PS：不需要绑定
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2.某个Activity需要同一应用中的Service为其单独服务，当此Activity消毁时，也将为其服务的Service一并消毁。
PS：需要绑定
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3.多个Activity绑定到同一个Service，仅当所有Activity取消了绑定，Service才消毁。
PS：只有第一个Activity绑定时才调用onBind()方法，第二个、第三个....第N个直接取得第一个Activity绑定时onBind()方法返回的IBinder对象
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4.即使退出当前应用时，仍希望Service继续运行（如：上传或下载任务）；或者此Service为其他应用提供服务。
PS：需要跨进程通信（IPC）
4.1当远程服务不需要支持多线程时，使用Messager.
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Server端应用代码
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public class RemoteServiceProxy extends Service { public static final int GET_RESULT = 1; private final Messenger mMessenger = new Messenger(new Handler() { private int status = 0; @Override public void handleMessage(Message msg) { if (msg.what == GET_RESULT) { try { msg.replyTo.send(Message.obtain(null, GET_RESULT, status++, 0)); } catch (RemoteException e) { e.printStackTrace(); } } else { super.handleMessage(msg); } } }); @Override public IBinder onBind(Intent intent) { return mMessenger.getBinder(); }}?
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<service android:name=".module.photo.RemoteServiceProxy" android:process=":remote" />?
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Client端应用代码
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//开启一个服务bindService(new Intent(this, RemoteServiceProxy.class), mConnection, BIND_AUTO_CREATE);private Messenger mService;private ServiceConnection mConnection = new ServiceConnection() { @Override public void onServiceConnected(ComponentName name, IBinder service) { mService = new Messenger(service); } @Override public void onServiceDisconnected(ComponentName name) { }};?private Messenger mMessenger = new Messenger(new Handler() { @Override public void handleMessage(Message msg) { if (msg.what == RemoteServiceProxy.GET_RESULT) { Log.i("M", "From Remote Service "+msg.arg1); } else { super.handleMessage(msg); } }});Message message = Message.obtain(null, RemoteServiceProxy.GET_RESULT);message.replyTo = mMessenger;try { mService.send(message);} catch (RemoteException e) { e.printStackTrace();}??
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4.2当远程服务需要同时响应多个Client的请求，使用AIDL.
注意：一般我们应用中是不需要使用AIDL的，这里仅仅是为了学习和深入理解Android的IPC机制。
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Server端应用代码
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在Server端应用新建IRemoteService.aidl和IRemoteCallback.aidl文件，编辑内容如下
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package com.example.aidl;interface IRemoteCallback { void executeCallback(String msg);}?
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package com.example.aidl;import com.example.aidl.IRemoteCallback;interface IRemoteService { //注册回调 void register(IRemoteCallback callback); //取消注册回调 void unregister(IRemoteCallback callback); //执行回调 void execute(); //获取状态 int getStatus(String flag);}?
创建Service类为客户端提供服务
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package com.example.server.service;import com.example.aidl.IRemoteCallback;import com.example.aidl.IRemoteService;import android.app.Service;import android.content.Intent;import android.os.IBinder;import android.os.RemoteCallbackList;import android.os.RemoteException;import android.util.Log;public class RemoteService extends Service {@Overridepublic IBinder onBind(Intent intent) {return iBinder;}private final RemoteCallbackList<IRemoteCallback> remoteCallbackList = new RemoteCallbackList<IRemoteCallback>(); private IRemoteService.Stub iBinder = new IRemoteService.Stub() {@Overridepublic void register(IRemoteCallback cb) throws RemoteException {if (cb != null) remoteCallbackList.register(cb);}@Overridepublic void unregister(IRemoteCallback cb) throws RemoteException {if (cb != null) remoteCallbackList.unregister(cb);}@Overridepublic void execute() throws RemoteException {int size = remoteCallbackList.beginBroadcast();while (size > 0) {size--;remoteCallbackList.getBroadcastItem(size).executeCallback("Hello, Client.");}remoteCallbackList.finishBroadcast();Log.i("RS", "RemoteService.execute() has done.");}int status;@Overridepublic int getStatus(String flag) throws RemoteException {Log.i("RS", "RemoteService.getStatus(flag) flag is "+flag);if ("reset".equals(flag)) status = 0;return status++;}};}?
在AndroidManifast.xml中配置Service，必需设置Action过滤
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<service android:name=".server.service.RemoteService" android:process=":remote"> <intent-filter> <action android:name="test.remote.service"/> </intent-filter></service>?
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Client端应用代码
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将Server端创建的IRemoteService.aidl和IRemoteCallback.aidl文件copy到Client端应用中
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在Client端获取Server端的RemoteService对象的引用
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package com.example;import com.example.aidl.IRemoteCallback;import com.example.aidl.IRemoteService;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.os.RemoteException;import android.view.View;import android.view.View.OnClickListener;import android.widget.Toast;public class ClientActivity extends Activity {@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.client_activity);/* 绑定远程服务，与其他进程Service通信。 注意：Client需要通过Action与RemoteService绑定，因为Client端是没有RemoteService.class的 */this.bindService(new Intent("test.remote.service"), sConnection, BIND_AUTO_CREATE);this.findViewById(R.id.execute_callback).setOnClickListener(mOnClickListener);this.findViewById(R.id.get_status).setOnClickListener(mOnClickListener);}private OnClickListener mOnClickListener = new OnClickListener() {@Overridepublic void onClick(View button) {try {if (button.getId() == R.id.execute_callback) remoteService.execute();else {int remoteStatus = remoteService.getStatus("set");Toast.makeText(getApplicationContext(), "Status: "+remoteStatus+" is from RemoteService", Toast.LENGTH_LONG).show();}} catch (RemoteException e) {e.printStackTrace();}}};private IRemoteService remoteService;//远程服务private ServiceConnection sConnection = new ServiceConnection() {@Overridepublic void onServiceConnected(ComponentName name, IBinder service) {remoteService = IRemoteService.Stub.asInterface(service);//注册回调try {remoteService.register(remoteCallback);} catch (RemoteException e) {e.printStackTrace();}}@Overridepublic void onServiceDisconnected(ComponentName name) {//意外断开连接时回调remoteService = null;}};private IRemoteCallback.Stub remoteCallback = new IRemoteCallback.Stub() {@Overridepublic void executeCallback(String msg) throws RemoteException {Toast.makeText(getApplicationContext(), "ClientActivity: "+msg, Toast.LENGTH_LONG).show();}};}??
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1 楼 wangguangji 2011-11-29 怎么你的这些代码 都编辑不能通过呢！不好意思我是初学android 2 楼 wangguangji 2011-11-29 不好意思 是我不会弄！是可以运行的！