AIDL的概念不說了,一般都是Activity調(diào)用service的方法去獲取一些東西,但是如何做到service主動回調(diào)activity的方法去推送一些東西的,這種需求一般也是會有的(比如后臺有個定位,每次位置更新或者位置分生一定程度的變化的時候就要主動向Ui發(fā)送一個消息去通知ui發(fā)生變化,當(dāng)然可以用廣播,但是廣播是很耗費資源的)
那么如何實現(xiàn)呢
1)先創(chuàng)建倆個aidl文件,

文件IMyAidlInterface 為一個回調(diào)注冊,注銷的接口,可能有很多個地方需要監(jiān)聽這個service變化,所以我們要把他存儲起來

interface IMyAidlInterface {
    void registerListener(IListener listener);

    void unregisterListener(IListener listener);
}

IListener 文件是真真執(zhí)行回調(diào)的接口,我們activity創(chuàng)建一個IListener 調(diào)用IMyAidlInterface 注冊起來

interface IListener {
      void onReceiver(String msg);
}

2)創(chuàng)建我們自己的service,并實現(xiàn)一系列方法
模擬一個handler來更新數(shù)據(jù),在onbind成功之后開始推送數(shù)據(jù)(一定要bing成功之后再操作),回調(diào)集合應(yīng)為進程間是不同步的,所以我們用google官方推薦的一個RemoteCallbackList來操作,該集合內(nèi)部已經(jīng)處理了相關(guān)的操作,是線程同步的,具體用法就不寫了.
在service中我們創(chuàng)建一個 IMyAidlInterface.Stub 的實例,onbind中返回.并實現(xiàn)這倆個方法.

public class MyService extends Service {
    private int count = 0;
    private RemoteCallbackList<IListener> demandList = new RemoteCallbackList<>();
    @SuppressLint("HandlerLeak")
    private Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);

            if (demandList != null) {
                int nums = demandList.beginBroadcast();
                for (int i = 0; i < nums; i++) {
                    try {
                        count++;
                        demandList.getBroadcastItem(i).onReceiver(String.valueOf(count));
                    } catch (RemoteException e) {
                        e.printStackTrace();
                    }
                }
                demandList.finishBroadcast();
            }
            mHandler.sendEmptyMessageDelayed(1000, 100);//每3s推一次消息
        }
    };

    IMyAidlInterface.Stub stub = new IMyAidlInterface.Stub() {

        @Override
        public void registerListener(IListener listener) {
            demandList.register(listener);
        }

        @Override
        public void unregisterListener(IListener listener) {
            demandList.unregister(listener);
          }
    };

    public MyService() {

    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        mHandler.sendEmptyMessageDelayed(1000, 100);
        return stub;
    }


    @Override
    public void onCreate() {
        super.onCreate();
    }

  
}

3)客戶端注冊
在客戶端activity中我們啟動這個服務(wù)(5.0系統(tǒng)已經(jīng)禁止隱式的啟動服務(wù)),然后我們調(diào)用iMyAidlInterface.registerListener方法去注冊一個監(jiān)聽

  /**
     * 啟動服務(wù)
     */
    private void starService() {
        Intent intent = new Intent(this, MyService.class);
        bindService(intent, new ServiceConnection() {
            @Override
            public void onServiceConnected(ComponentName name, IBinder service) {
                iMyAidlInterface = IMyAidlInterface.Stub.asInterface(service);
               // Log.e("registerListener", iMyAidlInterface.toString());
                try {
                    iMyAidlInterface.registerListener(stub);
                    Log.e("registerListener", "registerListener");
                } catch (RemoteException e) {
                    e.printStackTrace();
                }
            }

            @Override
            public void onServiceDisconnected(ComponentName name) {
                Log.e("ComponentName", name.getClassName());
            }
        }, BIND_AUTO_CREATE);
    }

監(jiān)聽器如下,onReceiver方法回調(diào)實際上并非在ui線程,他在binder的線程池中執(zhí)行,所以我們寫個handler來刷新ui

stub = new IListener.Stub() {
            @Override
            public void onReceiver(String msg) throws RemoteException {
                Message obtain = Message.obtain();
                obtain.obj=msg;
                handler.sendMessage(obtain);
            }
        };
--------------------------------------------------------------------------------
  private Handler handler=new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            String obj = (String) msg.obj;
            if (info!=null){
                info.setText(obj);
            }
        }
    };

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