正如文档所说，我试图了解 intentService 如何在单个后台线程中完成所有工作。所以我潜入源代码，并有一个问题
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();
}
所以在 onCreate 服务中创建了一个 HandlerThread。在此之后，所有 onStartCommand 调用将消息添加到 HanlderThread 队列。
但是假设服务接收到多个意图，并将所有意图添加到队列中。但是在处理完第一条消息之后，handleMessage 中 onHandleIntent 之后的下一个调用是stopSelf(msg.arg1); . 据我了解，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，因此调用 onCreate 并创建另一个 HandlerThread！！, 之后没有几个 Worker 线程，不像文档所说的 Single 。有人可以解释一下，我哪里错了吗？