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Editor to share with you how Android uses Sensor to achieve sensor functions. I hope you will get something after reading this article. Let's discuss it together.

The details are as follows

I. the use of sensors

1. Type of sensor:

Direction sensor:: Sensor.TYPE_ORIENTATION

Acceleration (gravity) sensor: sensor.TYPE_ACCELEFOMETER

Light sensor: sensor.TYPT_LIGHT

Magnetic field sensor: sensor.TYPE_MANGNETIC_FIELD

Distance (proximity) sensor: Sensor.TYPE_FROXIMITY

Temperature sensor: Sensor.TYPE_TEMPERATURE

Commonly used API:

Get the service of the sensor (the manager who gets the sensor)

SensorManager sm= (SensorManager) getSystemService (SENSOR_SERVICE)

Get all the types of sensors supported by the phone:

List list=sm.getSensorList (SensorManager.TYPE_ALL)

Type of sensor:

Sensor.getType ()

The name of the sensor

Sensor.getName ()

Sensor monitoring: SensorEventListener ()

Sm.registerListener (monitoring, sensor object, rate)

Key points:

Light sensor: sensor.TYPT_LIGHT

Get the ray value: float f=event.values [0]

WindowManager.LayoutParams params = activity.getWindow () .getAttributes ()

Params.screenBrightness = value / 255f

Activity.getWindow () setAttributes (params)

Acceleration sensor: sensor.TYPE_ACCELEFOMETER

Acceleration has three values: these three values are the acceleration of the phone in three directions

Float x=event.values [0];-> at the top of the phone, from the left edge to the edge is the positive direction of the phone's X axis.

Float y=event.values [1];-> from the top of the phone along the left side of the phone along the bottom of the phone is the positive direction of the Y axis

Float z=event.values [2];-> the vertical phone screen is facing outward in a positive direction

Direction sensor: Sensor.TYPE_ORIENTATION

Three values of the direction sensor:

Bearing: when the phone is lying flat, the head of the phone rotates around the Z axis, including the angle with the positive north pole of the earth.

0 stands for North (North)

90 stands for East East

180 stands for South

270stands for West

Overlooking angle: the angle between the rotation of the mobile phone around the X axis and the horizontal line

Roll angle: the angle between the rotation of the phone around the Y axis and the horizontal line

Using Direction Sensor to realize the Application of Compass

The results after running are as follows:

Layout file (activity_main.xml)

I

Java Code (MainActivity)

Package com.example.g150825_android29;import android.content.Context;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.util.Log;import android.view.View;import android.view.WindowManager;import android.view.animation.Animation;import android.view.animation.RotateAnimation;import android.widget.ImageView;import android.widget.TextView;import java.util.List Public class MainActivity extends AppCompatActivity {private SensorManager sensorManager; private Sensor sensorOri; private TextView tv_main_result; private MyListener myListener; private ImageView iv_image; private float current=0; @ Override protected void onCreate (Bundle savedInstanceState) {super.onCreate (savedInstanceState); setContentView (R.layout.activity_main); tv_main_result = (TextView) findViewById (R.id.tv_main_result) Iv_image = (ImageView) findViewById (R.id.iv_image); / / get the sensor manager sensorManager = (SensorManager) getSystemService (Context.SENSOR_SERVICE); / / get the light sensor / / sensorLight = sensorManager.getDefaultSensor (Sensor.TYPE_LIGHT); / / get the accelerometer / / sensorACC = sensorManager.getDefaultSensor (Sensor.TYPE_ACCELEROMETER) / / get the direction sensor sensorOri=sensorManager.getDefaultSensor (Sensor.TYPE_ORIENTATION); / / get the light sensor value (ray value) myListener = new MyListener ();} / / register monitoring (listening for a sensor value) @ Override protected void onResume () {super.onResume (); sensorManager.registerListener (myListener,sensorOri,SensorManager.SENSOR_DELAY_UI) } class MyListener implements SensorEventListener {/ / when the value is changed @ Override public void onSensorChanged (SensorEvent sensorEvent) {float [] fancisensorEvent.values; float xfolf [0]; float yellowf [1]; float zefff [2]; tv_main_result.setText ("x =" + x + "\ ny=" + y + "\ nz=" + z) / instantiate the rotation animation RotateAnimation rotateAnimation=new RotateAnimation (current,-x, Animation.RELATIVE_TO_SELF,0.5f, Animation.RELATIVE_TO_SELF,0.5f); rotateAnimation.setDuration (200); current=-x; iv_image.startAnimation (rotateAnimation); / / change the brightness of the screen / / WindowManager.LayoutParams layoutParams=getWindow () .getAttributes () / / layoutParams.screenBrightness=light/255f;// getWindow () .setAttributes (layoutParams);} / when the precision of the value changes @ Override public void onAccuracyChanged (Sensor sensor, int I) {}} / / Unregister the listener @ Override protected void onDestroy () {super.onDestroy (); sensorManager.unregisterListener (myListener) } / / public void getAllSensors (View view) {/ / List sensors=sensorManager.getSensorList (Sensor.TYPE_ALL); / / for (Sensors: sensors) {/ / Log.i ("test", s.getName ()) / /} /}} after reading this article, I believe you have a certain understanding of "how Android uses Sensor to achieve sensor functions". If you want to know more about it, please follow the industry information channel. Thank you for reading!

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