Android

之前看了一篇，然后不自己动手肯定是不行的，然后自己又写了一遍。

背景：

一般使用messenger进行进程间通信的时候，我们只能进行单方向通信。但是有没有办法让服务器端和客户端进行双向通信呢？

解决思路：

在第一次消息交互的时候，将客户端的消息队列作为一个对象传给服务端，让服务端取到客户端的消息队列。这样就可以实现双向通信了。

代码如下：

需要注意的是，远程绑定service的地方，需要加上包名，不要忘记。 

重点关注红色部分，其余的地方没有什么好说的啦。

服务端代码

package com.example.xxx.server_testmsger;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

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

package com.example.xxx.server_testmsger;

import android.app.Service;
import android.content.Intent;
import android.media.MediaRecorder;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Messenger;
import android.os.RemoteException;
import android.util.Log;

public class serverService extends Service {
    private static final int MSG_WHAT = 1;
    private static final int REQUEST_KEYEVENT = 1;
    private static final int MSG_TOCLIENT = 2;
    private static final int REQUEST_KEYEVENT_TOCLIENT = 2;
    private Messenger mMessenger_from_client = null;

    public serverService() {
    }

    private Messenger mMessager = new Messenger(new Handler() {
        @Override
        public void handleMessage(Message msg) {
            Log.d("Server MSG", "handleMessage()");
            super.handleMessage(msg);

            mMessenger_from_client = (Messenger)msg.obj;
            Message message = msg.obtain(msg);
            Log.d("Server MSG", message.toString());
            switch (message.what) {
                case MSG_WHAT:
                    Message msgToClient = new Message();
                    msgToClient.what=MSG_TOCLIENT;
                    msgToClient.arg1=REQUEST_KEYEVENT_TOCLIENT;
                    try {
                        Log.d("Server MSG", "sending message....");
                        mMessenger_from_client.send(msgToClient);
                    } catch (RemoteException e) {
                        e.printStackTrace();
                    }
                    break;
                default:
                    break;
            }
        }

    });

    @Override
    public IBinder onBind(Intent intent) {
        return mMessager.getBinder();
    }
}

客户端代码

package com.example.xxx.client_testmsger;

import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Messenger;
import android.os.RemoteException;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.ContextThemeWrapper;
import android.view.View;
import android.widget.Button;

import java.io.InputStream;

public class MainActivity extends AppCompatActivity {
    private Messenger mMessenger = null;
    private Messenger mServiceMessenger = null;
    private Intent serviceIntent;
    private static final int MSG_WHAT = 1;
    private static final int REQUEST_KEYEVENT = 1;
    private static final int MSG_TOCLIENT = 2;
    private static final int REQUEST_KEYEVENT_TOCLIENT = 2;

    private Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            switch (msg.what) {
                case MSG_TOCLIENT:
                    Log.e("Client MSG","got Message from server");
                    Log.e("Client MSG",msg.toString());
                    break;
                default:
                    break;
            }
        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        serviceIntent = new Intent();
        serviceIntent.setComponent(new ComponentName("com.example.xxx.server_testmsger","com.example.xxx.server_testmsger.serverService"));
        bindService(serviceIntent, mConnection, Context.BIND_AUTO_CREATE);
        mMessenger = new Messenger(mHandler);
    }

    private ServiceConnection mConnection = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            Log.e("MSG","MainActivity Start");
            Log.d("Client MSG", "onServiceConnected()");
            if (service == null) {
                mServiceMessenger = null;
            } else {
                mServiceMessenger = new Messenger(service);
                Message message = new Message();
                message.what = MSG_WHAT;
                message.arg1 = REQUEST_KEYEVENT;
                message.obj = mMessenger;
                try {
                    Log.d("Client MSG", "Message send()");
                    mServiceMessenger.send(message);
                } catch (RemoteException e) {
                    e.printStackTrace();
                }
            }
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            Log.d("Client MSG", "onServiceDisconnected()");
            mServiceMessenger = null;
        }
    };

    @Override
    public void onDestroy() {
        super.onDestroy();
        unbindService(mConnection);
    }
}