android基础---- AIDL服务的使用

　　AIDL和其他的IDL类似，它允许你定义程序接口，以便客户端与服务器端通过IPC机制交互。在android上面，一个进程一般不能访问另外进程的内存。因此，Android平台将这些跨进程访问的对象分解成操作系统能够识别的简单对象。并为跨应用访问而特殊编排和整理这些对象。用于编排和整理这些对象的代码编写起来十分冗长，所以Android的AIDL提供了相关工具来自动生成这些代码。今天，我们开始AIDL的学习。

一，AIDL的定义：

它是一种android内部进程通信接口的描述语言，通过它我们可以定义进程间的通信接口

二、AIDL的开发流程：

定义AIDL文件(先在服务端定义，客户端也要定义，内容跟服务端一样)
服务端实现接口
客户端调用接口

具体的aidl的说明： http://www.cnblogs.com/popapa/p/android_aidl.html

AIDL的简单使用之定义 AIDL 接口

为了测试，我写了aidl服务器端和aidl客户端!

aidl服务器端

项目结构如下：

android基础---->AIDL服务的使用

一、创建.aidl文件：IRemoteAIDL.aidl

// IRemoteAIDL.aidl
package com.huhx.linux;

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

interface IRemoteAIDL {
    int add(int a, int b);
}

二、定义服务类：RemoteService.java

package com.huhx.linux.aidlserver;

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

import com.huhx.linux.IRemoteAIDL;

public class RemoteService extends Service {
    private final static String TAG = "RemoteService";

    private IRemoteAIDL.Stub binder = new IRemoteAIDL.Stub() {
        @Override
        public int add(int a, int b) throws RemoteException {
            Log.i(TAG, "a = " + a + ", b = " + b);
            return a + b;
        }
    };

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

三、在AndroidManifest.xml文件中声明服务：

<service android:name=".RemoteService" android:enabled="true" android:exported="true" />

aidl客户端

项目结构如下：

android基础---->AIDL服务的使用

一、创建与服务器端一样的aidl文件： IRemoteAIDL.aidl

// IRemoteAIDL.aidl
package com.huhx.linux;

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

interface IRemoteAIDL {
    int add(int a, int b);
}

二、在MainActivity中，得到远程服务并调用它的方法。

package com.huhx.linux.aidlclient;

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.os.RemoteException;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Toast;

import com.huhx.linux.IRemoteAIDL;

public class MainActivity extends AppCompatActivity {
    private IRemoteAIDL iRemoteAIDL;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        binServices();
    }

    private ServiceConnection conn = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            iRemoteAIDL = IRemoteAIDL.Stub.asInterface(service);
        }
        @Override
        public void onServiceDisconnected(ComponentName name) {
            iRemoteAIDL = null;
        }
    };

    // 绑定服务
    private void binServices() {
        Intent intent = new Intent();
        intent.setComponent(new ComponentName("com.huhx.linux.aidlserver", "com.huhx.linux.aidlserver.RemoteService"));
        bindService(intent, conn, Context.BIND_AUTO_CREATE);
    }

    // 处理相加的方法
    public void addMethod(View view) {
        try {
            int result = iRemoteAIDL.add(3, 4);
            Toast.makeText(MainActivity.this, "3 + 4 = " + result, Toast.LENGTH_SHORT).show();
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }
}

三、根据aidl文件，android生成的接口如下(可以不关注)：

/*
 * This file is auto-generated.  DO NOT MODIFY.
 * Original file: J:\\android\\andridtest\\andridtest\\2016-02-29\\BaseTest8\\aidlclient\\src\\main\\aidl\\com\\huhx\\linux\\IRemoteAIDL.aidl
 */
package com.huhx.linux;
// Declare any non-default types here with import statements

public interface IRemoteAIDL extends android.os.IInterface
{
/** Local-side IPC implementation stub class. */
public static abstract class Stub extends android.os.Binder implements com.huhx.linux.IRemoteAIDL
{
private static final java.lang.String DESCRIPTOR = "com.huhx.linux.IRemoteAIDL";
/** Construct the stub at attach it to the interface. */
public Stub()
{
this.attachInterface(this, DESCRIPTOR);
}
/**
 * Cast an IBinder object into an com.huhx.linux.IRemoteAIDL interface,
 * generating a proxy if needed.
 */
public static com.huhx.linux.IRemoteAIDL asInterface(android.os.IBinder obj)
{
if ((obj==null)) {
return null;
}
android.os.IInterface iin = obj.queryLocalInterface(DESCRIPTOR);
if (((iin!=null)&&(iin instanceof com.huhx.linux.IRemoteAIDL))) {
return ((com.huhx.linux.IRemoteAIDL)iin);
}
return new com.huhx.linux.IRemoteAIDL.Stub.Proxy(obj);
}
@Override public android.os.IBinder asBinder()
{
return this;
}
@Override public boolean onTransact(int code, android.os.Parcel data, android.os.Parcel reply, int flags) throws android.os.RemoteException
{
switch (code)
{
case INTERFACE_TRANSACTION:
{
reply.writeString(DESCRIPTOR);
return true;
}
case TRANSACTION_add:
{
data.enforceInterface(DESCRIPTOR);
int _arg0;
_arg0 = data.readInt();
int _arg1;
_arg1 = data.readInt();
int _result = this.add(_arg0, _arg1);
reply.writeNoException();
reply.writeInt(_result);
return true;
}
}
return super.onTransact(code, data, reply, flags);
}
private static class Proxy implements com.huhx.linux.IRemoteAIDL
{
private android.os.IBinder mRemote;
Proxy(android.os.IBinder remote)
{
mRemote = remote;
}
@Override public android.os.IBinder asBinder()
{
return mRemote;
}
public java.lang.String getInterfaceDescriptor()
{
return DESCRIPTOR;
}
@Override public int add(int a, int b) throws android.os.RemoteException
{
android.os.Parcel _data = android.os.Parcel.obtain();
android.os.Parcel _reply = android.os.Parcel.obtain();
int _result;
try {
_data.writeInterfaceToken(DESCRIPTOR);
_data.writeInt(a);
_data.writeInt(b);
mRemote.transact(Stub.TRANSACTION_add, _data, _reply, 0);
_reply.readException();
_result = _reply.readInt();
}
finally {
_reply.recycle();
_data.recycle();
}
return _result;
}
}
static final int TRANSACTION_add = (android.os.IBinder.FIRST_CALL_TRANSACTION + 0);
}
public int add(int a, int b) throws android.os.RemoteException;
}

IRemoteAIDL.java