由于一直在做上层App，与AIDL接触的真心很少，上层应用之间的交互使用AIDL不多，可以使用Broadcast、ContentProvider等等。但是最近确实被AIDL摆了一道，决定认真调试一下。
AIDL其实是一个IPC通信机制， 即进程之间也可以相互通信，传递有效数据，那么怎么创建或者说需要什么呢？首先交互需要服务端和客户端，其次主要的方式创建aidl文件，其实质还是通过service进行交互。

1.AIDLServer

1.1 Person的创建

package com.example.edwardadmin.aidlmodel;

import android.os.Parcel;
import android.os.Parcelable;

/**
 * Created by EdwardAdmin on 2017/9/24.
 */

public class Person implements Parcelable {

    private String mUserName;
    private String mUserAge;

    public Person(String username, String userage) {
        mUserName = username;
        mUserAge = userage;
    }

    public String getmUserName() {
        return mUserName;
    }

    public String getmUserAge() {
        return mUserAge;
    }

    @Override
    public String toString() {
        return super.toString();
    }

    protected Person(Parcel in) {
        mUserName = in.readString();
        mUserAge = in.readString();
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(mUserName);
        dest.writeString(mUserAge);
    }

    @Override
    public int describeContents() {
        return 0;
    }

    public static final Creator<Person> CREATOR = new Creator<Person>() {
        @Override
        public Person createFromParcel(Parcel in) {
            return new Person(in);
        }

        @Override
        public Person[] newArray(int size) {
            return new Person[size];
        }
    };
}

注意点：

Model类需要实现 Parcelable，重写重要方法

1.2 IPersonAidlInterface.aidl创建

// IPersonAidlInterface.aidl
package com.example.edwardadmin.aidl;

parcelable Person;

注意点：

parcelable 是小写

1.3 IRomteAidlInterface.aidl创建

// IRomteAidlInterface.aidl
package com.example.edwardadmin.aidl;

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

interface IRomteAidlInterface {
    /**
     * Demonstrates some basic types that you can use as parameters
     * and return values in AIDL.
     */
    void basicTypes(int anInt, long aLong, boolean aBoolean, float aFloat,
            double aDouble, String aString);

    String getPersonUserName();
    String getPersonUserAge();

}

1.4 RmoteService的创建

package com.example.edwardadmin.service;

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

import com.example.edwardadmin.aidl.IRomteAidlInterface;
import com.example.edwardadmin.aidlmodel.Person;

/**
 * Created by EdwardAdmin on 2017/9/24.
 */

public class RmoteService extends Service {

    private static final String TAG = "RmoteService";

    private Person mPerson;
    private String mUserName;
    private String mUserAge;

    @Override
    public void onCreate() {
        super.onCreate();
    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        Log.d(TAG, "onBind Service success!");
        mPerson = new Person("Edward", "24");
        return new RomteBinder();
    }

    class RomteBinder extends IRomteAidlInterface.Stub {

        @Override
        public void basicTypes(int anInt, long aLong, boolean aBoolean, float aFloat, double aDouble, String aString) throws RemoteException {

        }

        @Override
        public String getPersonUserName() throws RemoteException {
            mUserName = mPerson.getmUserName();
            Log.d(TAG, "Person mUserName = " + mUserName);
            return mUserName;
        }

        @Override
        public String getPersonUserAge() throws RemoteException {
            mUserAge = mPerson.getmUserAge();
            Log.d(TAG, "Person mUserAge = " + mUserAge);
            return mUserAge;
        }
    }

    @Override
    public boolean onUnbind(Intent intent) {
        return super.onUnbind(intent);
    }
}

1.5 AndroidManifest.xml创建

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.example.edwardadmin.aidlserver">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>

        <service android:name="com.example.edwardadmin.service.RmoteService">
            <intent-filter>
                <action android:name="android.intent.action.RESPOND_AIDL_MESSAGE"></action>
            </intent-filter>
        </service>
    </application>

</manifest>

1.6 AIDLServer项目结构

AIDLServer项目结构图

2.AIDLClient创建

2.1 copy aidl to client.

2.2 Connect & Acquire

package com.example.edwardadmin.aidl;

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.IBinder;
import android.os.RemoteException;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import java.util.List;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";
    private static final String BIND_SERVICE_ACTION = "android.intent.action.RESPOND_AIDL_MESSAGE";

    private IRomteAidlInterface iRomteAidlInterface;

    private Button mConnectButton;
    private Button mAcquireButton;

    private String mUsername;
    private String mUserage;

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

    private void initView() {
        mConnectButton = (Button) this.findViewById(R.id.connect);
        mAcquireButton = (Button) this.findViewById(R.id.acquire_info);

        mConnectButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                bindService();
            }
        });

        mAcquireButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (null != iRomteAidlInterface) {
                    try {
                        mUsername = iRomteAidlInterface.getPersonUserName();
                        mUserage = iRomteAidlInterface.getPersonUserAge();
                        Toast.makeText(getApplicationContext(), "mUsername = " + mUsername + ",mUserage = " + mUserage, Toast.LENGTH_SHORT).show();
                    } catch (RemoteException e) {
                        e.printStackTrace();
                    }
                }
            }
        });
    }

    ServiceConnection serviceConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
            iRomteAidlInterface = IRomteAidlInterface.Stub.asInterface(iBinder);
        }

        @Override
        public void onServiceDisconnected(ComponentName componentName) {
            iRomteAidlInterface = null;
        }
    };

    private void bindService() {
        Intent serviceIntent = new Intent();
        serviceIntent.setAction(BIND_SERVICE_ACTION);
        //serviceIntent.setComponent(new ComponentName("com.example.edwardadmin.aidlserver", "com.example.edwardadmin.service.RmoteService"));
        final Intent eintent = new Intent(achieveExplicitFromImplicitIntent(this, serviceIntent));
        bindService(serviceIntent, serviceConnection, Context.BIND_AUTO_CREATE);
        Log.d(TAG, "bindService");
    }

    private void unBindSevice() {
        unbindService(serviceConnection);
        Log.d(TAG, "unbindService");
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unBindSevice();
    }

    public Intent achieveExplicitFromImplicitIntent(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;
        Log.d(TAG,"packageName = " + packageName);
        Log.d(TAG,"className = " + className);
        ComponentName component = new ComponentName(packageName, className);
        
        Intent explicitIntent = new Intent(implicitIntent);

        explicitIntent.setComponent(component);
        return explicitIntent;
    }
}

2.3 AIDLClient项目结构

AIDLClient项目结构图

Question1.当AIDLClient创建成功之后，Service连接不上？

Answer：

1).Intent 除了必要的Action，还需要ComponentName，参数packageName："AIDLServer->AndroidMainfest.xml->package",参数className："AIDLServer->Service完整的包名+ServiceName"

2).如果第一点不清楚的，调用achieveExplicitFromImplicitIntent方法，获取正确的Intent。

Github地址：
AIDLServer：https://github.com/EricWinner/AIDLServer
AIDLClient：https://github.com/EricWinner/AIDLClient

有任何问题，欢迎指出.