Question

正如docmentation所说，我试图了解intentService如何在单一后台线程中完成所有工作。所以我深入研究源代码，并提出问题

    public abstract class IntentService extends Service {
    private volatile Looper mServiceLooper;
    private volatile ServiceHandler mServiceHandler;
    private String mName;
    private boolean mRedelivery;
    private final class ServiceHandler extends Handler {
        public ServiceHandler(Looper looper) {
            super(looper);
        }
        @Override
        public void handleMessage(Message msg) {
            onHandleIntent((Intent)msg.obj);
            stopSelf(msg.arg1);
        }
    }
    /**
     * Creates an IntentService.  Invoked by your subclass's constructor.
     *
     * @param name Used to name the worker thread, important only for debugging.
     */
    public IntentService(String name) {
        super();
        mName = name;
    }


    public void setIntentRedelivery(boolean enabled) {
        mRedelivery = enabled;
    }
    @Override
    public void onCreate() {
        // TODO: It would be nice to have an option to hold a partial wakelock
        // during processing, and to have a static startService(Context, Intent)
        // method that would launch the service & hand off a wakelock.
        super.onCreate();
        HandlerThread thread = new HandlerThread("IntentService[" + mName + "]");
        thread.start();
        mServiceLooper = thread.getLooper();
        mServiceHandler = new ServiceHandler(mServiceLooper);
    }
    @Override
    public void onStart(Intent intent, int startId) {
        Message msg = mServiceHandler.obtainMessage();
        msg.arg1 = startId;
        msg.obj = intent;
        mServiceHandler.sendMessage(msg);
    }
    /**
     * You should not override this method for your IntentService. Instead,
     * override {@link #onHandleIntent}, which the system calls when the IntentService
     * receives a start request.
     * @see android.app.Service#onStartCommand
     */
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        onStart(intent, startId);
        return mRedelivery ? START_REDELIVER_INTENT : START_NOT_STICKY;
    }
    @Override
    public void onDestroy() {
        mServiceLooper.quit();
}

因此在onCreate服务中创建了一个HandlerThread。在此之后，所有onStartCommand调用都会向HanlderThread队列添加消息但是假设服务接收了几个意图，并将所有意图添加到队列中。但在处理第一个消息后，在handleMessage中的onHandleIntent之后的下一个调用是 stopSelf（msg.arg1）; 。据我所知，在此之后，服务被破坏，但HandlerThread继续处理消息。在销毁之后，假设我再发送一个服务意图。由于intentservice被销毁，这会调用onCreate并创建另一个HandlerThread !! ，之后没有几个Worker线程，不像Single那样文档说。有人可以解释我，我错了吗？

Answer 1

据我了解，此后，服务被销毁

没有。如果您致电stopSelf()，服务将停止。但是，如果没有其他未提交的stopSelf(int)已发送到服务，Intents将仅停止服务。

IntentService和HandlerThread计数

1 个答案: