android aidl淺析

1.創建aidl文件
在android studio下 點擊項目 new–>AIDL–>aidl file
然後點擊 make project（ctrl + F9）後 會在 app\build\generated\source\aidl\debug\com\bskuai\aidltest\aidl*IMyAidlInterface.java*

IMyAidlInterface.java 文件就是ide幫我們自動生成的java文件

2.創建service

package com.bskuai.aidltest;

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

import com.bskuai.aidltest.aidl.IMyAidlInterface;

public class MyService extends Service {

    private final IMyAidlInterface.Stub mBinder = new IMyAidlInterface.Stub() {
        @Override
        public void basicTypes(int anInt, long aLong, boolean aBoolean, float aFloat, double aDouble, String aString) throws RemoteException {

        }

        @Override
        public void add() throws RemoteException {
            Log.e("tag","add");
        }

        @Override
        public void delete() throws RemoteException {
            Log.e("tag","delete");
        }
    };

    public MyService() {
    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        return mBinder;
    }
}

3.綁定Service

  private ServiceConnection serviceConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            myAidlInterface = IMyAidlInterface.Stub.asInterface(service);

        }

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

   Intent intent = new Intent(this,MyService.class);
        this.bindService(intent,serviceConnection, Context.BIND_AUTO_CREATE);

4.配置服務

  <service
            android:name=".MyService"
            android:enabled="true"
            android:exported="true"
            android:process=":remote"
            >
        </service>

android:process=”:remote” 讓服務運行在 包名:remote 的進程中

以上已經實現不同進程間的通信

5.瞭解自動生成的IMyAidlInterface.java

在客戶端中我們 使用了 myAidlInterface = IMyAidlInterface.Stub.asInterface(service);

asInterface()方法

 public static com.bskuai.aidltest.aidl.IMyAidlInterface asInterface(android.os.IBinder obj) {
            if ((obj == null)) {
                return null;
            }
            android.os.IInterface iin = obj.queryLocalInterface(DESCRIPTOR);
            if (((iin != null) && (iin instanceof com.bskuai.aidltest.aidl.IMyAidlInterface))) {
                return ((com.bskuai.aidltest.aidl.IMyAidlInterface) iin);
            }
            return new com.bskuai.aidltest.aidl.IMyAidlInterface.Stub.Proxy(obj);
        }

如果傳進來的obj 爲null 直接返回 null 通過 queryLocalInterface 得到IInterface對象 如果 該對象不爲null 並且和IMyAidlInterface 是同一類型 強轉後返回該對象 否則返回Proxy 代理對象

onTransact()負責對自己定義的接口方法的調用

  @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_basicTypes: {
                    data.enforceInterface(DESCRIPTOR);
                    int _arg0;
                    _arg0 = data.readInt();
                    long _arg1;
                    _arg1 = data.readLong();
                    boolean _arg2;
                    _arg2 = (0 != data.readInt());
                    float _arg3;
                    _arg3 = data.readFloat();
                    double _arg4;
                    _arg4 = data.readDouble();
                    java.lang.String _arg5;
                    _arg5 = data.readString();
                    this.basicTypes(_arg0, _arg1, _arg2, _arg3, _arg4, _arg5);
                    reply.writeNoException();
                    return true;
                }
                case TRANSACTION_add: {
                    data.enforceInterface(DESCRIPTOR);
                    this.add();
                    reply.writeNoException();
                    return true;
                }
                case TRANSACTION_delete: {
                    data.enforceInterface(DESCRIPTOR);
                    this.delete();
                    reply.writeNoException();
                    return true;
                }
            }
            return super.onTransact(code, data, reply, flags);
        }

調用時通過code來匹配 下面的 int值

 static final int TRANSACTION_basicTypes = (android.os.IBinder.FIRST_CALL_TRANSACTION + 0);
        static final int TRANSACTION_add = (android.os.IBinder.FIRST_CALL_TRANSACTION + 1);
        static final int TRANSACTION_delete = (android.os.IBinder.FIRST_CALL_TRANSACTION + 2);