Activity与Service通信之AIDL远程服务

一、原理

http://note.youdao.com/yws/public/redirect/share?id=dbfce2a37b24ddc0ffff4722221e0e65&type=false

其实简单来说，AIDL可以实现应用程序之间进行通信。
二、使用Android studio创建AIDL

 如何创建可以查看《Android Studio 创建AIDL》，这里就不再累述了。

其中：AIDL文件

package testndk.testserviceaidl;

// Declare any non-default types here with import statements

interface ICountService {
/**
* Demonstrates some basic types that you can use as parameters
* and return values in AIDL.
*/
int getCount();
}

注意：
        Service 和Client中AIDL文件所在的包名必须一致，记得创建后要记得Rebuild 一下，不然没有办法使用；
Rebuild后，系统会自动生成类似xxx.Stub的类。
        这样我们就可以在Service端使用了如下：

class AIDLServerBinder extends ICountService.Stub{
@Override
public int getCount() throws RemoteException {
return i;
}
}

      在Client端使用如下：

private ServiceConnection serConn = new ServiceConnection() {

@Override
public void onServiceDisconnected(ComponentName name) {
iCountService = null;
}

@Override
public void onServiceConnected(ComponentName name, IBinder service) {
iCountService = ICountService.Stub.asInterface(service);
}
};

二、使用隐式意图启动服务
在Service端我们注册服务是这样的：

<service android:name="AIDLServer"
android:process=":remote">
<intent-filter>
<action android:name="testndk.testserviceaidl.AIDLServer" />
</intent-filter>
</service>

在client端启动该服务时，我们需要action如下：

Intent intent = new Intent("testndk.testserviceaidl.AIDLServer");

但是，在这里有个问题就是Android 5.0以后不支持隐式意图启动服务（会报参数异常）。那么我们怎么才能够启动该远程服务？
   解决方案，使用如下的方法把隐式意图转为显示意图，然后才启动服务就好了。

/***
* Android L (lollipop, API 21) introduced a new problem when trying to invoke implicit intent,
* "java.lang.IllegalArgumentException: Service Intent must be explicit"
*
* If you are using an implicit intent, and know only 1 target would answer this intent,
* This method will help you turn the implicit intent into the explicit form.
*
* Inspired from SO answer: http://stackoverflow.com/a/26318757/1446466 * @param context
* @param implicitIntent - The original implicit intent
* @return Explicit Intent created from the implicit original intent
*/
public static Intent createExplicitFromImplicitIntent(Context context, Intent implicitIntent) {
// Retrieve all services that can match the given intent
PackageManager pm = context.getPackageManager();
List<ResolveInfo> resolveInfo = pm.queryIntentServices(implicitIntent, 0);

// Make sure only one match was found
if (resolveInfo == null || resolveInfo.size() != 1) {
return null;
}

// Get component info and create ComponentName
ResolveInfo serviceInfo = resolveInfo.get(0);
String packageName = serviceInfo.serviceInfo.packageName;
String className = serviceInfo.serviceInfo.name;
ComponentName component = new ComponentName(packageName, className);

// Create a new intent. Use the old one for extras and such reuse
Intent explicitIntent = new Intent(implicitIntent);

// Set the component to be explicit
explicitIntent.setComponent(component);

return explicitIntent;
}

三、核心代码：
Service：

import java.util.Timer;
import java.util.TimerTask;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.RemoteException;

public class AIDLServer extends Service {
private static final int TIME = 1;
private Timer mTimer = null;
private int i = 0;

private AIDLServerBinder serviceBinder = new AIDLServerBinder();

class AIDLServerBinder extends ICountService.Stub{
@Override
public int getCount() throws RemoteException {
return i;
}
}

@Override
public void onCreate() {
super.onCreate();
mTimer = new Timer();
mTimer.schedule(new MyTimerTask(), 0,TIME * 1000);
}

@Override
public void onDestroy() {
super.onDestroy();
if(mTimer!=null){
mTimer.cancel();
mTimer = null;
}
}

@Override
public IBinder onBind(Intent intent) {
return serviceBinder;
}

class MyTimerTask extends TimerTask{

@Override
public void run() {
if(i==100){
i=0;
}
i++;
}
}
}

其中MainActivity没有处理，记得要先运行该程序才可以。
Client：

import java.util.List;
import java.util.Timer;
import java.util.TimerTask;

import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.RemoteException;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;

import testndk.testserviceaidl.ICountService;

public class AIDLClientActivity extends Activity {
private static final int TIME = 1;
private Button startBtn = null;
private Button stopBtn = null;
private TextView mTextView = null;
private ProgressBar mProgressBar = null;
private boolean mIsBind;
private Timer mTimer = null;
/**获取ICountService实例*/
private ICountService iCountService = null;
/**开启服务的显示意图*/
private Intent eintent;

Handler mHandler = new Handler(){
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
try {
int count =  iCountService.getCount();
mTextView.setText(count+"%");
mProgressBar.setProgress(count);
} catch (RemoteException e) {
e.printStackTrace();
}
}
};
private ServiceConnection serConn = new ServiceConnection() {

@Override
public void onServiceDisconnected(ComponentName name) {
iCountService = null;
}

@Override
public void onServiceConnected(ComponentName name, IBinder service) {
iCountService = ICountService.Stub.asInterface(service);
}
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

mTimer = new Timer();
Intent intent = new Intent("testndk.testserviceaidl.AIDLServer");
//把隐式意图转为显示意图
eintent = new Intent(createExplicitFromImplicitIntent(this,intent));
mTextView = (TextView)findViewById(R.id.loading_Tv);
mProgressBar = (ProgressBar)findViewById(R.id.myProgressBar);
mProgressBar.setMax(100);
startBtn = (Button)findViewById(R.id.start_Btn);
stopBtn = (Button)findViewById(R.id.stop_Btn);
startBtn.setOnClickListener(new ButtonClickListener());
stopBtn.setOnClickListener(new ButtonClickListener());

}

class ButtonClickListener implements OnClickListener{

@Override
public void onClick(View v) {
if(startBtn==v){
mIsBind = bindService(eintent, serConn, BIND_AUTO_CREATE);
if (mTimer == null){
mTimer = new Timer();
}
mTimer.schedule(new MyTimerTask(), 1000 ,TIME * 1000);
}else if (stopBtn==v) {
if(mIsBind){
unbindService(serConn);
if(mTimer!=null){
mTimer.cancel();
mTimer = null;
}
mIsBind = false;
}
}
}

}

class MyTimerTask extends TimerTask{
@Override
public void run() {
mHandler.sendMessage(mHandler.obtainMessage());
}
}

/***
* Android L (lollipop, API 21) introduced a new problem when trying to invoke implicit intent,
* "java.lang.IllegalArgumentException: Service Intent must be explicit"
*
* If you are using an implicit intent, and know only 1 target would answer this intent,
* This method will help you turn the implicit intent into the explicit form.
*
* Inspired from SO answer: http://stackoverflow.com/a/26318757/1446466 * @param context
* @param implicitIntent - The original implicit intent
* @return Explicit Intent created from the implicit original intent
*/
public static Intent createExplicitFromImplicitIntent(Context context, Intent implicitIntent) {
// Retrieve all services that can match the given intent
PackageManager pm = context.getPackageManager();
List<ResolveInfo> resolveInfo = pm.queryIntentServices(implicitIntent, 0);

// Make sure only one match was found
if (resolveInfo == null || resolveInfo.size() != 1) {
return null;
}

// Get component info and create ComponentName
ResolveInfo serviceInfo = resolveInfo.get(0);
String packageName = serviceInfo.serviceInfo.packageName;
String className = serviceInfo.serviceInfo.name;
ComponentName component = new ComponentName(packageName, className);

// Create a new intent. Use the old one for extras and such reuse
Intent explicitIntent = new Intent(implicitIntent);

// Set the component to be explicit
explicitIntent.setComponent(component);

return explicitIntent;
}

@Override
protected void onDestroy() {
super.onDestroy();
if(mTimer!=null){
mTimer.cancel();
mTimer = null;
}
if (mIsBind){
unbindService(serConn);
}
}

}

源码下载地址：
http://download.csdn.net/detail/lu1024188315/9537991
效果图：