[Android] Accelerometer 值

package com.accelerometer;import android.app.Activity;import android.hardware.Sensor;import android.hardware.SensorEvent;import android.hardware.SensorEventListener;import android.hardware.SensorManager;import android.os.Bundle;import android.widget.Button;import android.widget.TextView;public class AccelerometerActivity extends Activity {    /** Called when the activity is first created. */float x,y,z;SensorManager sensormanager = null;Sensor accSensor = null;TextView txt_x = null;TextView txt_y = null;TextView txt_z = null;Button btnExit = null;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                sensormanager = (SensorManager)getSystemService(SENSOR_SERVICE);        accSensor  = sensormanager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);                txt_x = (TextView)findViewById(R.id.txt_x);        txt_y = (TextView)findViewById(R.id.txt_y);        txt_z = (TextView)findViewById(R.id.txt_z);                       sensormanager.registerListener(new accSensorListener(), accSensor, SensorManager.SENSOR_DELAY_NORMAL);           }public class accSensorListener implements SensorEventListener    {@Overridepublic void onAccuracyChanged(Sensor arg0, int arg1) {}@Overridepublic void onSensorChanged(SensorEvent event) {if(event.sensor == accSensor){x = event.values[SensorManager.DATA_X];y = event.values[SensorManager.DATA_Y];z = event.values[SensorManager.DATA_Z];txt_x.setText("X: " + x);txt_y.setText("Y: " + y);txt_z.setText("Z: " + z);}}        }}