Messenger--信使

来源：互联网发布：石家庄专业关键词优化编辑：程序博客网时间：2024/04/28 23:05

Messenger可以在不同进程中传递Message对象，是一种轻量级的IPC方案，它的底层实现是AIDL。它对AIDL做了封装，使得我们可以更简单地进行进程间通信。它一次处理一个请求，因此在服务端我们不用考虑线程同步的问题。

//服务端public class MessengerService extends Service{    private static final String TAG="MessengerService";    //接收消息  并且处理消息    private static class MessengerHandler extends Handler{        public void handleMessage(Message msg){            switch(msg.what){                case MyConstants.MSG_FROM_CLIENT::                    Log.i(TAG,"receive msg from Client:"+msg.getData().getString("msg"));                    //接收客户端发送的消息之后进行响应                    Messenger client=msg.replyTo;                    Messenge  replyMessenge =Message.obtain(null,MyConstants,MSG_FROM_SERVICE);                    Bundle bundle=new Bundle();                    bundle.putString("reply","恩，你的消息我已经收到，稍后会回复你！");                    replyMessage.setData(bundle);                    try{                        client.send(replyMessage);                    }catch(Exception e){                        e.printStackTrace();                    }                    break;                default:                    super.handleMessage(msg);            }        }    }    //将Messenger与Handler进行关联    private final Messenger mMessenger =new Messenger(new MessengerHandler());    //返回Messenger对象底层的Binder对象    public IBinder onBind(Intent intent){        return mMessenger.getBinder();    }}

//客户端public class MessengerActivity extends Activity{    private static final String TAG="MessengerActivity";    private Messenger mService;    //接收服务端 onBind()方法返回的IBinder对象    private ServiceConnection mConnection =new ServiceConnection(){        public void onServiceConnected(ComponentName className,IBinder service){            //创建一个可以向服务器发送消息的Messenger对象            mService =new Messenger(service);            //构建消息对象            Messenger msg=Message.obtain(null,MyConstants.MSG_FROM_CLIENT);            Bundle data=new Bundle();  //利用Bundle来进行数据的传输            data.putString("msg","hello,this is client.");            msg.setData(data);            /////////////            //接收服务端回复的Messenger通过Message的replyTo参数传递给服务端            msg.replyTo = mGetReplyMessenger;            ////////////            try{                mService.send(msg);            }catch(Exception e){                e.printStackTrace();            }        }        public void onServiceDisconnected(ComponentName className){        }    };    ////////    //接收服务端的回复    private Messenger mGetReplyMessenger =new Messenger(new MessengerHandler());    private static class MessengerHandler extends Handler{        public void handleMessage(Message msg){            switch(msg.what){                case MyConstants.MSG_FROM_SERVICE:                    Log.i(TAG,"receive msg from Service:"+msg.getData().getString("reply"));                    break;                default:                    super.handleMessage(msg);            }        }    }    ////////    protected void onCreate(Bundle savedInstanceState){        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_messenger);        Intent intent =new Intent(this,MessengerService.class);        bindService(intent,mConnection,Context.BIND_AUTO_CREATE);    }    protected void onDestroy(){        unbindService(mConnection);        super.onDestroy();    }}

0 0