在Android系统中，各应用程序都运行在各自的系统中，进程之间无法直接进行数据的交换。如果需要通信，就需要使用AIDL。

一、创建AIDL文件

package com.example.aidlexample;
interface Dog{
	String getDogName();
	String getDogWeight();
}

二、将Service里的数据暴露出来

当访问者启动DogDescribe 服务时，将返回一个IBinder对象给访问者。访问者利用这个对象，就可以进行数据访问。

package com.example.aidlexample;

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

import com.example.aidlexample.Dog.Stub;

public class DogDescribe extends Service {

	private String dogweight;
	private String dogname;
	private DogBinder dogbinder;
//将IBinder对象返回给访问者
	@Override
	public IBinder onBind(Intent intent) {
		// TODO Auto-generated method stub
		return dogbinder;
	}

	@Override
	public void onCreate() {
		// TODO Auto-generated method stub
		super.onCreate();
		dogbinder = new DogBinder();
	}

	// 继承自动代码生成的类Stub（实现了IBinder接口）
	public class DogBinder extends Stub {

		@Override
		public String getDogName() throws RemoteException {
			// TODO Auto-generated method stub
			return "xiaokeai";
		}

		@Override
		public String getDogWeight() throws RemoteException {
			// TODO Auto-generated method stub
			return "30kg";
		}

	}

}

访问者利用bindService(),在一个activity中，以bind方式启动一个Service。同时拿到一个Binder对象。

package com.example.aidlexample;

import android.app.Activity;
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;

public class MainActivity extends Activity {

	private Dog doginfo;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		Intent it = new Intent();
		ComponentName comp = new ComponentName(MainActivity.this,
				DogDescribe.class);
		it.setComponent(comp);
		bindService(it, conn, Service.BIND_AUTO_CREATE);
	}

	private ServiceConnection conn = new ServiceConnection() {

		@Override
		public void onServiceDisconnected(ComponentName name) {
			// TODO Auto-generated method stub
			System.out.println("service disconn");
		}

		@Override
		public void onServiceConnected(ComponentName name, IBinder service) {
			// TODO Auto-generated method stub
			doginfo = Dog.Stub.asInterface(service);
			try {
				System.out.println("serviceconnected" + doginfo.getDogName()
						+ doginfo.getDogWeight());
			} catch (RemoteException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
	};

	@Override
	protected void onDestroy() {
		// TODO Auto-generated method stub
		super.onDestroy();
		this.unbindService(conn);
		System.out.println("service unbind");
	}
}

AIDL用法详解