SENSOR_ACCELEROMETER异常

Question

我想在服务中注册一个SENSOR_ACCELEROMETER，但事实证明这是一个无关紧要的问题。以下是我的代码：

 asensor = new AccerSensor(context);//the sensoreventlistener
 Log.i("wogua", "creating"+asensor.toString());
 manager.registerListener(asensor,manager.getDefaultSensor(SensorManager.SENSOR_ACCELEROMETER), SensorManager.SENSOR_DELAY_FASTEST);


 Exception:

Caused by: java.lang.NullPointerException::

    at com.wogua.mobileprotected.service.LostProtectService.onCreate(LostProtectService.java:36)

我不知道问题是什么，sensoreventlistener的实例不是null :::: com.wogua.mobileprotected.sensor.AccerSensor@41bf3f20

怎么可能是null，::: manager =（SensorManager）context.getSystemService（Context.SENSOR_SERVICE）;

Answer 1

这是适合我的方式：

    mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
    mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);

    if (mAccelerometer != null) {
        // Success! There's an accelerometer
        mSensorManager.registerListener(this, mAccelerometer,
                SensorManager.SENSOR_DELAY_FASTEST);
    } else {
        Toast.makeText(this, "This device doesnt support accelerometer",
                Toast.LENGTH_SHORT).show();
        stopSelf();
    }

Answer 2

manager未初始化，超过确定