Android跨进程监听(ALDL)

背景 : 后台服务处理接收数据，在数据变化时回调给监听的客户端APP

实现方式采用android提供的ALDL

1.后台服务进程(服务器端)

1.新建ALDL文件

注册和移除监听

package com.test.music;
// 监听接口
import com.test.music.IMusicStatusListener;

interface IMusicServiceInterface {
    //添加监听
    void addMusicStatusListener(IMusicStatusListener listener);
    //移除监听
    void removeMusicStatusListener(IMusicStatusListener listener);
}

监听接口

package com.test.music;

interface IMusicStatusListener {

    void onModeChange(int mode);
}

aldl文件位置如下图所示 :
在这里插入图片描述

2.service中处理逻辑

// Service
class ObserveService : Service() {
    //跨进程监听
    private val remoteCallbackList =
        RemoteCallbackList<IMusicStatusListener>()

   
    override fun onBind(intent: Intent): IBinder? {
        return ObserveServiceStub()
    }
 
   
   //在状态变化时调用
    private fun onMusicModeChanged(mode: Int) {
        for (i in 0 until remoteCallbackList.beginBroadcast()) {
            try {
                remoteCallbackList.getBroadcastItem(i)
                    .onModeChange(mode)
            } catch (e: RemoteException) {
                e.printStackTrace()
            }
        }
        remoteCallbackList.finishBroadcast()
    }
    
    //添加和移除监听的Bind
    inner class ObserveServiceStub : IMusicServiceInterface.Stub() {
        override fun removeMusicStatusListener(listener: IMusicStatusListener?) {
            listener?.let {
                remoteCallbackList.unregister(it)
            }
        }

        override fun addMusicStatusListener(listener: IMusicStatusListener?) {
            listener?.let {
                remoteCallbackList.register(it)
            }
        }
    }
 }

2.客户端App(监听服务器端变化)

1.复制服务器端ALDL文件到相同位置

在这里插入图片描述

2. 客户端连接服务

    private IMusicServiceInterface iMusicServiceInterface;
    private InternalMusicStatusListener internalMusicStatusListener;
    private ServiceConnection serviceConnection;
    Intent serviceIntent = new Intent();
    //服务端的package
    serviceIntent.setPackage(MUSIC_PACKAGE);
    
    /**
     *       <intent-filter>
     *           <action android:name="com.test.musicplayer.ObserveService" />
     *       </intent-filter>
     */
    //设置Action 即Service中AndroidManifest.xml的XML
    
    serviceIntent.setAction(MUSIC_ACTION);
    serviceConnection = new ServiceConnection() {
            @Override
            public void onServiceConnected(ComponentName name, IBinder service) {
               //固定写法
                iMusicServiceInterface = IMusicServiceInterface.Stub.asInterface(service);
                try {
                    // 连接成功后添加监听
                    iMusicServiceInterface.addMusicStatusListener(internalMusicStatusListener);
                } catch (RemoteException e) {
                    e.printStackTrace();
                }
            }

            @Override
            public void onServiceDisconnected(ComponentName name) {
                 //在服务器断开连接还可以处理自动连接的逻辑

            }
        };
   //绑定服务     
   getContext().bindService(serviceIntent, serviceConnection, Context.BIND_AUTO_CREATE);
   internalMusicStatusListener = new InternalMusicStatusListener();
   
   //服务连接后添加监听，在此监听状态回调
   private class InternalMusicStatusListener extends IMusicStatusListener.Stub {
        @Override
        public void onModeChange(int mode) throws RemoteException {
            updateMusicModeIcon(mode);
        }
    }