Android Widget onReceive无法调用Service类？

    ...
   <service android:name=".MyService" />
</application>

@Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager, int[] appWidgetIds) {
    ...
    Intent intent = new Intent(context, MyService.class);
    PendingIntent pendingIntent = PendingIntent.getService(context, 0, intent, 0);
    remoteViews.setOnClickPendingIntent(R.id.widget_button, pendingIntent);
    ...
}

public class MyService extends Service {
    ...
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        // 在这里处理Service的生命周期
        ...
        return START_STICKY;
    }
    ...
}

<uses-permission android:name="android.permission.INTERNET" />

Log.d("MyService", "Service started");