從ScheduledExecutorService發送廣播

Question

當我嘗試使用LocalBroadcastManager從ScheduledExecutorService發送任何操作時，似乎尚未發送（或尚未發送）實際操作。 這是代碼示例：

public class SomeService extends IntentService {
    private static final String TAG = SomeService.class.getSimpleName();
    public static final String ACTION = "some-action";

    private ScheduledExecutorService scheduledTaskExecutor = Executors.newScheduledThreadPool(1);

    public SomeService() {
        super(TAG);
    }

    @Override
    protected void onHandleIntent(Intent intent) {
        String action = intent.getAction();
        if (action.equals("scheduled_action")) {
            scheduledTaskExecutor.schedule(new ScheduledAction(ACTION), 10, SECONDS);
        } else if (action.equals("send_it_now")) {
            sendAction(ACTION);
        }
    }

    private void sendAction(String action) {
        Log.d(TAG, "send action [" + action + "]");
        Intent intent = new Intent(action);
        LocalBroadcastManager.getInstance(SomeService.this).sendBroadcast(intent);
    }

    // it also could be Callable, but effect is pretty the same
    private class ScheduledAction implements Runnable {
        final String action;

        ScheduledAction(String action) {
            this.action = action;
        }

        @Override
        public void run() {
            sendAction(action);
        }
    }
}

根據傳入的操作，服務會立即發送ACTION或在10秒后發送。 這是已訂閱ACTION ：

public class SomeActivity extends Activity {
    private static final String TAG = SomeActivity.class.getName();
    private BroadcastReceiver actionReceiver = new ActionReceiver();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        IntentFilter filter = new IntentFilter();
        filter.addAction(SomeService.ACTION);
        LocalBroadcastManager.getInstance(this).registerReceiver(actionReceiver, filter);
    }

    @Override
    protected void onDestroy() {
        LocalBroadcastManager.getInstance(this).unregisterReceiver(actionReceiver);
        super.onDestroy();
    }

    private class ActionReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            Log.d(TAG, "received action [" + action + "]");
        }
    }
}

在send_it_now情況下，一切都會按預期進行：

Intent intent = new Intent(..., SomeService.class);
intent.setAction("send_it_now");
startService(intent); 

我看到適當的消息已打印到logcat：

...
SomeService send action [some-action]
SomeActivity received action [some-action] 
...

但是當我嘗試使用scheduled_action ：

Intent intent = new Intent(..., SomeService.class);
intent.setAction("scheduled_action");
startService(intent);

我看到已發送動作，但活動中未收到該動作：

...
SomeService send action [some-action]
...

因此，有人可以說出這段代碼有什么問題嗎，或者至少說明我可以找到解釋的方向？

一些更新。 如果出於相同的目的使用Timer和TimerTask ，則使用ScheduledExecutorService和ScheduledFuture-它可以工作！

Answer 1

由於您不在UI線程上，請嘗試以下操作：

public void run() { Looper.prepare(); sendAction(action); Looper.loop(); }

public void run()
{
    new AsyncTask<Void, Void, Void>()
    {
        @Override
        protected Void doInBackground(Void... params)
        {
            return null;
        }

        protected void onPostExecute(Void result)
        {
            sendAction(action);
        }
    }.execute();
}