Android 传感器的使用

package com.example.a91920.sensor;

import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;

import java.util.List;

public class MainActivity extends AppCompatActivity implements SensorEventListener{
private TextView tvSensors,proximity,accel;
private SensorManager mSensorManager;
private float[] gravity=new float[3];

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tvSensors= (TextView) findViewById(R.id.tvsensor);
proximity= (TextView) findViewById(R.id.proximity);
accel= (TextView) findViewById(R.id.accel);
//从系统服务中获得传感器管理器
mSensorManager= (SensorManager) getSystemService(SENSOR_SERVICE);
//从传感器管理器中获得全部的传感器列表
List<Sensor> sensors=mSensorManager.getSensorList(Sensor.TYPE_ALL);
//        显示每个传感器的信息
for(Sensor sensor:sensors)
{
tvSensors.append(sensor.getName()+"\n");
}
}

@Override
public void onSensorChanged(SensorEvent event) {
switch (event.sensor.getType()){
case Sensor.TYPE_ACCELEROMETER://加速度传感器
final float alpha= (float) 0.8;
gravity[0]=alpha*gravity[0]+(1-alpha)*event.values[0];
gravity[1]=alpha*gravity[1]+(1-alpha)*event.values[1];
gravity[2]=alpha*gravity[2]+(1-alpha)*event.values[2];
String accelerometer="加速度\n"+"X:"+(event.values[0]-gravity[0])+"\n"
+"Y:"+(event.values[1]-gravity[1])+"\n"
+"Z:"+(event.values[2]-gravity[2])+"\n";
accel.setText(accelerometer);
break;
case Sensor.TYPE_GRAVITY://重力传感器
gravity[0]=event.values[0];
gravity[1]=event.values[1];
gravity[2]=event.values[2];
break;
case Sensor.TYPE_PROXIMITY://距离传感器
proximity.setText(String.valueOf(event.values[0]));
break;
}
}

@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}

@Override
protected void onResume() {
super.onResume();
//注册相应的传感器
mSensorManager.registerListener(this,
mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
SensorManager.SENSOR_DELAY_UI);
mSensorManager.registerListener(this,
mSensorManager.getDefaultSensor(Sensor.TYPE_GRAVITY),
SensorManager.SENSOR_DELAY_FASTEST);
mSensorManager.registerListener(this,
mSensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY),
SensorManager.SENSOR_DELAY_UI);
}

@Override
protected void onPause() {
super.onPause();
mSensorManager.unregisterListener(this);
}
}