即使使用WakeLock,当Droid/Nexus One屏幕关闭时,Accelerometer也会停止提供样品

Question

我有一些代码可以扩展服务并在Android上记录onSensorChanged(SensorEvent事件)加速计传感器读数.我希望能够记录这些传感器读数,即使设备关闭(我对电池寿命非常小心,并且在运行时显而易见).虽然屏幕上的日志工作正常,但在2.0.1 Motorola Droid和2.1 Nexus One上.

但是,当手机进入休眠状态时(通过按下电源按钮),屏幕关闭,onSensorChanged事件停止传送(每隔N次使用一次Log.e消息进行验证onSensorChanged).

该服务获取wakeLock以确保它在后台运行; 但是,它似乎没有任何影响.我已经尝试了各种各样的PowerManager.唤醒锁,但它们似乎都不重要.

_WakeLock = _PowerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "My Tag");
_WakeLock.acquire();

关于在屏幕关闭时你是否能真正从传感器获取数据的报道相互矛盾......任何人都对更现代版的Android(Eclair)和硬件有任何经验吗？

这似乎表明它在Cupcake中工作:http: //groups.google.com/group/android-developers/msg/a616773b12c2d9e5

PS:完全相同的代码在G1上的1.5中按预期工作.当屏幕关闭,应用程序在后台等时,记录继续.

Answer 1

我们从2.0.1开始推断出这一点.这似乎是有意的,也许是电池寿命提升的一部分被吹捧为一个功能.我们有一个工作摇晃唤醒或解锁2.0,然后它打破了更新,我们无法得到任何解决方法.;'(如果保持CPU部分锁定并不总是阻止CPU休眠也没关系.从我看到的通过USB记录调试的情况看来偶尔会提到传感器监听器随睡眠的变化而变化.

用户发布了他声称可以在摩托罗拉设备上使用的解决方法 - https://sites.google.com/a/bug-br.org.br/android/technical-documents

我测试了解决方法,提出了教程中的以下代码和一些手动修订版(在他的教程中提供了一些"错误"代码):

public class ShakeWakeupService extends Service implements SensorEventListener{
     private Context mContext;
     SensorManager mSensorEventManager;
     Sensor mSensor;

     // BroadcastReceiver for handling ACTION_SCREEN_OFF.
     public BroadcastReceiver mReceiver = new BroadcastReceiver() {

         @Override
         public void onReceive(Context context, Intent intent) {
             // Check action just to be on the safe side.
             if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
                 Log.v("shake mediator screen off","trying re-registration");
                 // Unregisters the listener and registers it again.
                 mSensorEventManager.unregisterListener(ShakeWakeupService.this);
                 mSensorEventManager.registerListener(ShakeWakeupService.this, mSensor,
                     SensorManager.SENSOR_DELAY_NORMAL);
             }
         }
     };

         @Override
         public void onCreate() {
           super.onCreate();
           Log.v("shake service startup","registering for shake");
           mContext = getApplicationContext();
             // Obtain a reference to system-wide sensor event manager.
           mSensorEventManager = (SensorManager) mContext.getSystemService(Context.SENSOR_SERVICE);
             // Get the default sensor for accel
           mSensor = mSensorEventManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
             // Register for events.
           mSensorEventManager.registerListener(this, mSensor, SensorManager.SENSOR_DELAY_NORMAL);

             // Register our receiver for the ACTION_SCREEN_OFF action. This will make our receiver
             // code be called whenever the phone enters standby mode.
           IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_OFF);
           registerReceiver(mReceiver, filter);
     }

     @Override
     public void onDestroy() {
        // Unregister our receiver.
         unregisterReceiver(mReceiver);
         // Unregister from SensorManager.
         mSensorEventManager.unregisterListener(this);
     }

     @Override
     public IBinder onBind(Intent intent) {
         // We don't need a IBinder interface.
  return null;
     }

 public void onShake() {
         //Poke a user activity to cause wake?
     }
     public void onAccuracyChanged(Sensor sensor, int accuracy) {
                //not used right now
            }
            //Used to decide if it is a shake
            public void onSensorChanged(SensorEvent event) {
                    if(event.sensor.getType() != Sensor.TYPE_ACCELEROMETER) return;
                  Log.v("sensor","sensor change is verifying");
            }
      }

这个解决方法对我有用,但在我运行screebl时不起作用,这是我的很多用户真正希望与我正在开发的东西一起工作的功能.