Android Senser 使用方式

Android传感器有以下几种：
加速度传感器(accelerometer)
陀螺仪传感器(gyroscope)
环境光照传感器(light)
磁力传感器(magnetic field)
方向传感器(orientation)
压力传感器(pressure)
距离传感器(proximity)
温度传感器(temperature)
使用方法大体类似，都是先获取SensorMannager，然后实现SensorEventListener接口，再注册SensorEventListener，接口中有Senser获取到的数据的回调。
以下实现一个加速度传感器(accelerometer)的使用方法。

1 Activity中代码

public class MainActivity extends AppCompatActivity {    private Sensor graveSensor;    private SensorManager sensorManager;    private ViewDataBinding viewDataBinding;    private MainViewModel mainViewModel;    //保存 x y z 的坐标    float bx = 0;  float by = 0;  float bz = 0;    long bTime = 0;//这一次的时间    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        viewDataBinding = DataBindingUtil.setContentView(this, R.layout.activity_main);        mainViewModel = new MainViewModel();        viewDataBinding.setVariable(com.senser.BR.model, mainViewModel);        //1获取SensorMannager        sensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);        if (sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD) != null) {            List<Sensor> graveSensors = sensorManager.getSensorList(Sensor.TYPE_ACCELEROMETER);            graveSensor = graveSensors.get(0);        }    }    //2实现SensorEventListener接口    private SensorEventListener listener = new SensorEventListener() {        @Override        public void onSensorChanged(SensorEvent sensorEvent) {//S4enser获取到的数据            float x = sensorEvent.values[0];            float y = sensorEvent.values[1];            float z = sensorEvent.values[2];            long time=System.currentTimeMillis()-bTime;            float speadX = (x - bx) / ( time);//X轴的速度            float speadY = (y - by) / (time);  //y轴的速度            float speadZ = (z - bz) / (time);   //z轴的速度            mainViewModel.setX(speadX);            mainViewModel.setY(speadY);            mainViewModel.setZ(speadZ);            bx = x; by = y; bz = z;            bTime = System.currentTimeMillis();        }        @Override        public void onAccuracyChanged(Sensor sensor, int i) {        }    };    @Override    protected void onResume() {        super.onResume();        //注册SensorEventListener        sensorManager.registerListener(listener, graveSensor, SensorManager.SENSOR_DELAY_NORMAL);    }    @Override    protected void onDestroy() {        super.onDestroy();        sensorManager.unregisterListener(listener);    }}

2 viewModel中代码

import android.databinding.BaseObservable;import android.databinding.Bindable;import com.senser.BR;/** * Created by c9736 on 2017/7/10. */public class MainViewModel extends BaseObservable {    private float x, y, z;    @Bindable    public String getX() {        return "x="+x;    }    public void setX(float x) {        this.x = x;        notifyPropertyChanged(BR.x);    }    @Bindable    public String getY() {        return "y="+y;    }    public void setY(float y) {        this.y = y;        notifyPropertyChanged(BR.y);    }    @Bindable    public String getZ() {        return "z="+z;    }    public void setZ(float z) {        this.z = z;        notifyPropertyChanged(BR.z);    }}

3布局文件

<?xml version="1.0" encoding="utf-8"?><layout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools">    <data>        <variable            name="model"            type="com.senser.MainViewModel" />    </data>    <LinearLayout        android:id="@+id/activity_main"        android:layout_width="match_parent"        android:layout_height="match_parent"        android:orientation="vertical"        tools:context="com.senser.MainActivity">        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="@{model.x}" />        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="@{model.y}" />        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="@{model.z}" />    </LinearLayout></layout>