android Messenger 用法，demo，helloworld

如果你觉得写aidl比较麻烦，android还简单封装了一个 Messenger api，可以进行简单的跨进程通信，不过我干android这么多年，从来没有见过有哪个项目用过这玩意儿，因为太麻烦，还不如直接用aidl简单感觉，如果你是初学者，早点弃坑

1。

声明并实现一个service

package com.xbb.ipcdemo;

import android.app.Service;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Messenger;
import android.os.RemoteException;

// ipc with Android Messenger api
public class MsgrIpcService extends Service {

    private final class IncomingHandler extends Handler {
        @Override
        public void handleMessage(Message msg) {
            if (msg.what == Contract.Client.WHAT_TEXT) {
                Message message = Message.obtain(null, Contract.Client.WHAT_TEXT);
                Bundle bundle = new Bundle();
                bundle.putString("key_text", "msgr");
                message.obj = bundle;
                try {
                    msg.replyTo.send(message);
                } catch (RemoteException e) {
                    e.printStackTrace();
                }
            } else {
                super.handleMessage(msg);
            }
        }
    }

    final Messenger mMessenger = new Messenger(new IncomingHandler());

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

3。

在Activity中去bind一下

    private final Messenger clientMessenger = new Messenger(handler);

    private final ServiceConnection msgrConnection = new ServiceConnection() {

        @Override
        public void onServiceConnected(ComponentName className, IBinder service) {
            serviceMessenger = new Messenger(service);
            Message msg = Message.obtain(null, Contract.Client.WHAT_TEXT);
            Bundle bundle = new Bundle();
            bundle.putString(“key_text”, "hello");
            msg.obj = bundle;
            msg.replyTo = clientMessenger;
            try {
                serviceMessenger.send(msg);
            } catch (RemoteException e) {
                e.printStackTrace();
            }
        }

        @Override
        public void onServiceDisconnected(ComponentName className) {
            serviceMessenger = null;
        }
    };

    @Override
    protected void onStart() {
        super.onStart();
        bindService(new Intent(MainActivity.this, MsgrIpcService.class), msgrConnection,
                Context.BIND_AUTO_CREATE);
    }

有什么难度吗，没有