在文件SmsReceiverService.java文件中有這樣一段代碼
HandlerThread thread = new HandlerThread(TAG, Process.THREAD_PRIORITY_BACKGROUND);
thread.start();
mServiceLooper = thread.getLooper();
mServiceHandler = new ServiceHandler(mServiceLooper);
Message msg = mServiceHandler.obtainMessage();
msg.arg1 = startId;
msg.obj = intent;
mServiceHandler.sendMessage(msg);
HandlerThread繼承與Thread, HandlerThread有自己的消息隊列(Looper),一般HandlerThread和Handler類配合使用, Handler將消息發往HandlerThread的消息隊列, Handler處理消息。