Service

1、跨进程Messager 多应用间单线程

把Messenger比喻为一个信使，信使的作用是派信；那么Message就比喻为信件、信封，即信使派的东西；那么Bundle是什么呢？Message里面保存了Bundle，那么bundle可以比喻为信纸，信纸上写满了各种我们要传递的信息。读到这里，读者应该明白了这三者在Messenger通讯方式内所扮演的角色了。简单来说：Messenger把装有Bundle的Message发送到别的进程。
###客户端
private Messenger clientMessenger = new Messenger(handler);
private Handler handler = new Handler(Looper.getMainLooper()){
    @Override
    public void handleMessage(@NonNull Message msg) {
        super.handleMessage(msg);
        Bundle bundle = msg.getData();
        Log.i(TAG,"收到远程服务数据："+bundle.getString("service"));
    }
};

private void bindRemoteService(){
    Intent intent = new Intent();
    intent.setComponent(new ComponentName("com.example.xxx",
            "com.example.xxx.MessengerService"));
    boolean isBind = bindService(intent,conn, Service.BIND_AUTO_CREATE);
    Log.i(TAG,"bindRemoteService isBind="+isBind);
}
private Messenger messengerProxy;
ServiceConnection conn = new ServiceConnection() {
    @Override
    public void onServiceConnected(ComponentName name, IBinder iBinder) {
        Log.i(TAG,"onServiceConnected：");
        messengerProxy = new Messenger(iBinder);
    }

    @Override
    public void onServiceDisconnected(ComponentName name) {
        Log.i(TAG,"onServiceDisconnected：");
    }
};

private void sendData(){
    if (messengerProxy == null) return;
    Message message = new Message();
    message.replyTo = clientMessenger;
    Bundle bundle = new Bundle();
    bundle.putString("client","这是客户端发送数据："+messageid);
    message.setData(bundle);
    messengerProxy.send(message);
   }

###服务端
//创建服务端Messenger
private final Messenger mMessenger = new Messenger(messengerHandler);

@Override
public IBinder onBind(Intent intent) {
    //向客户端返回IBinder对象，客户端利用该对象访问服务端
    return mMessenger.getBinder();
}
  //拿到客户端的message 发送消息     
  private  Handler messengerHandler = new Handler(Looper.getMainLooper()) {
    @Override
    public void handleMessage(Message msg) {
        super.handleMessage(msg);
        //取出客户端的消息内容
        Bundle bundle = msg.getData();
        String clientMsg = bundle.getString("client");
        Log.i(TAG, "来自客户端的消息：" + clientMsg);
        //新建一个Message对象，作为回复客户端的对象
        Message message = Message.obtain();
        Bundle bundle1 = new Bundle();
        bundle1.putString("service", clientMsg+",服务端收到");
        message.setData(bundle1);
        try {
            msg.replyTo.send(message);
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }
};  

2、AIDL 多应用间多线程

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参数定向tag

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