Android系統中,各應用程序都運行在自己的進程中,通常情況下,各進程之間無法直接進行數據交換。爲了實現這種跨進程通信(InterProcess communication,簡稱IPC),Android提供了AIDL Service。
一、AIDL Service簡介
- Android的遠程Service調用與Java的遠程方法調用(RMI)基本相似,都是先定義一個遠程調用接口,然後爲該接口提供一個實現類。
- 本地Service的onBind方法會將Service的代理對象(IBinder對象)傳遞給客戶端,遠程Service的onBind方法會將IBinder對象的代理對象(Stub對象)傳遞給Service。
二、創建AIDL文件
package org.iti.tailyou.aidlservice;
interface ICount{
int getCount();
}
- AIDL定義的接口文件必須以.aidl結尾;
- AIDL接口中用到的數據類型,除了基本類型、String、List、Map、CharSequence外,其他類型都需要導包。
- 定義好aidl接口後,ADT工具會自動生成一個ICount.java接口,該接口中包含一個Stub內部類,該內部類實現了IBinder、ICount兩個接口。
三、定義Service實現類,將接口暴露給客戶端
package org.iti.tailyou.aidlservice;
import java.util.Timer;
import java.util.TimerTask;
import org.iti.tailyou.aidlservice.ICount.Stub;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.RemoteException;
public class AIDLService extends Service {
private int count = 0;
public class CountBinder extends Stub {
@Override
public int getCount() throws RemoteException {
return count;
}
}
@Override
public IBinder onBind(Intent arg0) {
new Timer().schedule(new TimerTask() {
@Override
public void run() {
count++;
}
}, 1000l,1000l);
return new CountBinder();
}
}
四、客戶端調用遠程Service
package org.iti.tailyou.aidlclient;
import org.iti.tailyou.aidlservice.ICount;
import android.app.Service;
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.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
public class MainActivity extends ActionBarActivity implements OnClickListener {
private ICount countService;
private ServiceConnection sc = new ServiceConnection() {
@Override
public void onServiceDisconnected(ComponentName name) {
}
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
countService = ICount.Stub.asInterface(service);
try {
Log.i("",
"------------------------count "
+ countService.getCount());
} catch (RemoteException e) {
e.printStackTrace();
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.btnBind).setOnClickListener(this);
findViewById(R.id.btnUnbind).setOnClickListener(this);
findViewById(R.id.btnGetCount).setOnClickListener(this);
}
@Override
public void onClick(View arg0) {
switch (arg0.getId()) {
case R.id.btnBind:
bindService(new Intent("org.iti.tailyou.aidlservice.AIDLService"),
sc, Service.BIND_AUTO_CREATE);
break;
case R.id.btnUnbind:
unbindService(sc);
break;
case R.id.btnGetCount:
try {
Log.i("",
"------------------------count "
+ countService.getCount());
} catch (RemoteException e) {
e.printStackTrace();
}
break;
default:
break;
}
}
}