我正在实现使用GPS数据的Android应用程序（尤其是GPS时间）。现在我在“GPSReader”类中使用接口“LocationListner”，它似乎只在协调发生变化时“收听”GPS数据。
我也试图将GPS数据存储在公共类“Common”中的全局变量“gpsTime”中，并使用它来自“SensorReader”类。在本课程中，我尝试循环获取GPS数据，如100 Hz，但是，正如我之前提到的，纬度，经度和GPS时间等数据有时不会改变，因为协调没有变化。我想使用GPS时间作为参考时间，所以想要周期性地获得它，例如100赫兹。我认为“LocationListner”是“被动的”，所以程序是否有任何“积极”的方式自行循环获取GPS数据？
提前非常感谢你。
这是“GPSReader”类，其中包含“LocationListner”。
package com.crowdsourcing.usgs;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.location.Criteria;
import android.location.GpsStatus;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.os.Binder;
import android.provider.Settings;
import android.widget.Toast;
import java.util.Random;
import Util.DateFormatter;
/**
* Created by TomokazuY on 9/14/2014.
*/
public class GPSReader extends Service implements LocationListener, GpsStatus.Listener, GpsStatus.NmeaListener {
private LocationManager locationManager;
Location location;
private String provider;
//gpsLog, gpsTime will be passed to SensorReader
public String gpsLog;
private long gpsTime;
private double latitude;
private double longitude;
private double altitude;
private float bearing;
private float accuracy;
private String gpsProvider;
public String nmea;
private long lastUpdate = 0;
//For global variable
Common common;
public void onGpsStatusChanged(int event) {
}
public void onNmeaReceived(long timestamp, String nmea)
{
this.nmea = "NMEA Sentence: "+ nmea;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
//For global variable
common=((Common)getApplicationContext());
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
// Define the criteria how to select the location provider -> use default
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setCostAllowed(false);
provider = locationManager.getBestProvider(criteria, false);
// the last known location of this provider
location = locationManager.getLastKnownLocation(provider);
common.initGPSTime = location.getTime();
// Initialize the location fields
if (location != null) {
this.onLocationChanged(location);
} else {
intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startService(intent);
}
// location updates: at least 1 meter and 200 milli secs change
// Both set to zero, which is the most aggressive setting.
// You’ll get a location update if any change in location is detected at any time.
// This setting can result in your app accessing the GPS provider as often as 50 –
//This can drain a fully charge Samsung Galaxy S III in less than 3 hours.
locationManager.requestLocationUpdates(provider, 0,0, this);
locationManager.addNmeaListener(this);
return START_STICKY;
}
@Override
public void onLocationChanged(Location location) {
// Called when a new location is found by the network location provider.
makeUseOfNewLocation(location);
}
@Override
public void onStatusChanged(String s, int i, Bundle bundle) {
}
@Override
public void onProviderEnabled(String s) {
Toast.makeText(this, "Enabled new provider " + provider,
Toast.LENGTH_SHORT).show();
}
@Override
public void onProviderDisabled(String s) {
Toast.makeText(this, "Disabled provider " + provider,
Toast.LENGTH_SHORT).show();
}
public void makeUseOfNewLocation(Location loc) {
latitude = loc.getLatitude();
longitude = loc.getLongitude();
altitude = loc.getAltitude();
bearing = loc.getBearing();
accuracy = loc.getAccuracy();
gpsProvider = loc.getProvider();
long curTime = System.currentTimeMillis();
long currentGpsTime = loc.getTime();
String currentGpsTimeString;
common.gpsTime = currentGpsTime;
currentGpsTimeString = DateFormatter.formatTimeStampM(common.gpsTime);
common.gpsLog = ",lat:," + latitude + ",long:," + longitude + ", alt:," + altitude
+ ", accuracy:," + accuracy + ", provider:,"+ gpsProvider
+ ", GPSTime:," + DateFormatter.formatTimeStampM(common.gpsTime)
+ ", ForGraph:," + curTime + "," + currentGpsTime
+ ", NMEA:," + nmea;
}
@Override
public void onDestroy() {
if(locationManager != null){
locationManager.removeUpdates(GPSReader.this);
}
}
// Binder given to clients
private final IBinder mBinder = new LocalBinder();
// Random number generator
private final Random mGenerator = new Random();
/**
* Class used for the client Binder. Because we know this service always
* runs in the same process as its clients, we don't need to deal with IPC.
*/
public class LocalBinder extends Binder {
GPSReader getService() {
// Return this instance of LocalService so clients can call public methods
return GPSReader.this;
}
}
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}
/** method for clients */
public long getGpsTime() {
return this.gpsTime;
}
//The function for gpsLog to be passed to SensorReader
public String getGpsLog() {
return gpsLog;
}
}
此处还有“SensorReader”类循环循环（有分配采样率的部分）。
package com.crowdsourcing.usgs;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.IBinder;
import android.widget.Toast;
import Util.DateFormatter;
import Util.FileCreator;
/**
* Created by SusanaLauH on 9/14/2014.
*/
public class SensorReader extends Service implements SensorEventListener{
//private final IBinder mBinder = new LocalBinder();
private SensorManager mSensorManager;
private Sensor accelerometerSensor, gyroscopeSensor, uncalGyroscopeSensor,
temperatureSensor, gravitySensor, lightSensor,
linearAccSensor, magnetSensor, uncalMagnetSensor,
airPressureSensor, humiditySensor, proximitySensor;
Boolean test;
Boolean isAccelerometer, isGyroscope, isUncalGyroscope, isMagnet, isUncalMagnet, isGravity,
isLinearAcceleration, isTemperature, isProximity, isHumidity, isPressure, isLight;
Boolean is1Hz, is5Hz, is50Hz, is100Hz;
float xA, yA, zA = 0;// Accelerometer
float xGy, yGy, zGy = 0; //Gyroscope
float xGyu, yGyu, zGyu = 0; //Uncalibrated gyroscope
float xGr, yGr, zGr; //Gravity
float xLA, yLA, zLA; //Linear Acceleration
float xMg, yMg, zMg; //Magnetic Field
float xMgu, yMgu, zMgu; //Uncalibrated magnetic field
float temperature, airPressure, humidity, proximity, light;
private long lastUpdate = 0;
//private long lastUpdate = System.currentTimeMillis();
int samplingRate = 1000; //Sampling rate = 1 Hz (units are in milliseconds)
GPSReader gpsReader = new GPSReader();
//Global variable
Common common;
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
Toast.makeText(this, "Starting reading sensors", Toast.LENGTH_SHORT).show();
//Global variable
common=((Common)getApplicationContext());
common.initSysTime = System.currentTimeMillis();
mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
accelerometerSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
gyroscopeSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_GYROSCOPE);
uncalGyroscopeSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_GYROSCOPE_UNCALIBRATED);
temperatureSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_AMBIENT_TEMPERATURE);
gravitySensor = mSensorManager.getDefaultSensor(Sensor.TYPE_GRAVITY);
lightSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_LIGHT);
linearAccSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_LINEAR_ACCELERATION);
magnetSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
uncalMagnetSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD_UNCALIBRATED);
airPressureSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_PRESSURE);
humiditySensor = mSensorManager.getDefaultSensor(Sensor.TYPE_RELATIVE_HUMIDITY);
proximitySensor = mSensorManager.getDefaultSensor(Sensor.TYPE_PROXIMITY);
//Using DELAY_FASTEST, the sensor will try to sensor the data as fast as possible.
//Use more system resources
mSensorManager.registerListener(this, accelerometerSensor, SensorManager.SENSOR_DELAY_FASTEST);
mSensorManager.registerListener(this, gyroscopeSensor, SensorManager.SENSOR_DELAY_FASTEST);
mSensorManager.registerListener(this, uncalGyroscopeSensor, SensorManager.SENSOR_DELAY_FASTEST);
mSensorManager.registerListener(this, temperatureSensor, SensorManager.SENSOR_DELAY_FASTEST);
mSensorManager.registerListener(this, gravitySensor, SensorManager.SENSOR_DELAY_FASTEST);
mSensorManager.registerListener(this, lightSensor, SensorManager.SENSOR_DELAY_FASTEST);
mSensorManager.registerListener(this, linearAccSensor, SensorManager.SENSOR_DELAY_FASTEST);
mSensorManager.registerListener(this, magnetSensor, SensorManager.SENSOR_DELAY_FASTEST);
mSensorManager.registerListener(this, uncalMagnetSensor, SensorManager.SENSOR_DELAY_FASTEST);
mSensorManager.registerListener(this, airPressureSensor, SensorManager.SENSOR_DELAY_FASTEST);
mSensorManager.registerListener(this, humiditySensor, SensorManager.SENSOR_DELAY_FASTEST);
mSensorManager.registerListener(this, proximitySensor, SensorManager.SENSOR_DELAY_FASTEST);
isAccelerometer = intent.getExtras().getBoolean("Accelerometer");
isGyroscope = intent.getExtras().getBoolean("Gyroscope");
isUncalGyroscope = intent.getExtras().getBoolean("UncalGyroscope");
isGravity = intent.getExtras().getBoolean("Gravity");
isMagnet = intent.getExtras().getBoolean("Magnet");
isUncalMagnet = intent.getExtras().getBoolean("UncalMagnet");
isLinearAcceleration = intent.getExtras().getBoolean("LinearAcceleration");
isLight = intent.getExtras().getBoolean(":Light");
isProximity = intent.getExtras().getBoolean("Proximity");
isPressure = intent.getExtras().getBoolean("Pressure");
isTemperature = intent.getExtras().getBoolean("Temperature");
isHumidity = intent.getExtras().getBoolean("Humidity");
is1Hz = intent.getExtras().getBoolean("1Hz");
is5Hz = intent.getExtras().getBoolean("5Hz");
is50Hz = intent.getExtras().getBoolean("50Hz");
is100Hz = intent.getExtras().getBoolean("100Hz");
//Toast.makeText(this, "Frequency 1: " + is1Hz, Toast.LENGTH_SHORT).show();
//Toast.makeText(this, "Frequency 5: " + is5Hz, Toast.LENGTH_SHORT).show();
//Toast.makeText(this, "Frequency 100: " + is100Hz, Toast.LENGTH_SHORT).show();
if (is1Hz == true){
samplingRate = 1000;
}
if (is5Hz == true){
samplingRate = 200;
}
if (is50Hz == true){
samplingRate = 20;
}
if (is100Hz == true) {//100 Hz
//samplingRate = 10;
samplingRate = 5;
}
//Detecting accelerometer
if (accelerometerSensor != null) {
Toast.makeText(this, "Accelerometer detected with MaxRange of: " + accelerometerSensor.getMaximumRange()
+ " and resolution of: " + accelerometerSensor.getResolution()
+ " and minDelay of: " + accelerometerSensor.getMinDelay(),
Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(this, "No accelerometer detected", Toast.LENGTH_SHORT).show();
}
//Detecting gyroscope
if (gyroscopeSensor != null) {
Toast.makeText(this, "Gyroscope detected", Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(this, "No gyroscope detected", Toast.LENGTH_SHORT).show();
}
//Detecting temperature sensor
if (temperatureSensor != null) {
Toast.makeText(this, "Temperature Sensor detected", Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(this, "No temperature sensor detected", Toast.LENGTH_SHORT).show();
}
//Detecting gravity sensor
if (gravitySensor != null) {
Toast.makeText(this, "Gravity Sensor detected", Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(this, "No gravity sensor detected", Toast.LENGTH_SHORT).show();
}
//Detecting light sensor
if (lightSensor != null) {
Toast.makeText(this, "Light Sensor detected", Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(this, "No light sensor detected", Toast.LENGTH_SHORT).show();
}
//Detecting magnetic field detector
if (magnetSensor != null) {
Toast.makeText(this, "Magnetic field Sensor detected", Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(this, "No magnetic field sensor detected", Toast.LENGTH_SHORT).show();
}
//Detecting air pressure sensor
if (airPressureSensor != null) {
Toast.makeText(this, "Air pressure Sensor detected", Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(this, "No Air pressure sensor detected", Toast.LENGTH_SHORT).show();
}
//Detecting humidity sensor
if (humiditySensor != null) {
Toast.makeText(this, "Humidity Sensor detected", Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(this, "No humidity sensor detected", Toast.LENGTH_SHORT).show();
}
//Detecting proximity sensor
if (proximitySensor != null) {
Toast.makeText(this, "Proximity Sensor detected", Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(this, "No proximity sensor detected", Toast.LENGTH_SHORT).show();
}
return START_STICKY;
}
@Override
public void onSensorChanged(SensorEvent sensorEvent) {
Sensor mSensor = sensorEvent.sensor;
//Accelerometer
if (mSensor.getType() == Sensor.TYPE_ACCELEROMETER && isAccelerometer == true) {
xA = sensorEvent.values[0];
yA = sensorEvent.values[1];
zA = sensorEvent.values[2];
}
//Gyroscope
if (mSensor.getType() == Sensor.TYPE_GYROSCOPE && isGyroscope == true) {
xGy = sensorEvent.values[0];
yGy = sensorEvent.values[1];
zGy = sensorEvent.values[2];
}
//-Uncalibrated Gyroscope
//Uncalibrated sensors provide more raw results and may include some bias,
// but their measurements contain fewer jumps from corrections applied through calibration
//Data is without drift compensation
if (mSensor.getType() == Sensor.TYPE_GYROSCOPE_UNCALIBRATED && isUncalGyroscope == true) {
xGyu = sensorEvent.values[0];
yGyu = sensorEvent.values[1];
zGyu = sensorEvent.values[2];
}
//Temperature
if (mSensor.getType() == Sensor.TYPE_AMBIENT_TEMPERATURE && isTemperature == true) {
temperature = sensorEvent.values[0];
}
//Gravity
if (mSensor.getType() == Sensor.TYPE_GRAVITY && isGravity == true) {
xGr = sensorEvent.values[0];
yGr = sensorEvent.values[1];
zGr = sensorEvent.values[2];
}
//Light
if (mSensor.getType() == Sensor.TYPE_LIGHT && isLight == true) {
light = sensorEvent.values[0];
}
//Linear Acceleration
if (mSensor.getType() == Sensor.TYPE_LINEAR_ACCELERATION && isLinearAcceleration == true) {
xLA = sensorEvent.values[0];
yLA = sensorEvent.values[1];
zLA = sensorEvent.values[2];
}
//Magnetic Field
if (mSensor.getType() == Sensor.TYPE_MAGNETIC_FIELD && isMagnet == true) {
xMg = sensorEvent.values[0];
yMg = sensorEvent.values[1];
zMg = sensorEvent.values[2];
}
//Uncalibrated Magnetic Field
if (mSensor.getType() == Sensor.TYPE_MAGNETIC_FIELD_UNCALIBRATED && isUncalMagnet == true) {
xMgu = sensorEvent.values[0];
yMgu = sensorEvent.values[1];
zMgu = sensorEvent.values[2];
}
//Air Pressure
if (mSensor.getType() == Sensor.TYPE_PRESSURE && isPressure == true) {
airPressure = sensorEvent.values[0];
}
//Humidity
if (mSensor.getType() == Sensor.TYPE_RELATIVE_HUMIDITY && isHumidity ==true) {
humidity = sensorEvent.values[0];
}
//Proximity
if (mSensor.getType() == Sensor.TYPE_PROXIMITY && isProximity == true) {
proximity = sensorEvent.values[0];
}
//Logging data
long curTime = System.currentTimeMillis();
//long curTime = gpsReader.getGpsTime();
//long gpsTime= common.gpsTime;
//Get the GPS time from GPSReader
String logTime = DateFormatter.formatTimeStampM(curTime);
if ((curTime - lastUpdate) > samplingRate) {
lastUpdate = curTime;
String log = logTime;
if (isAccelerometer == true){
log = log + ",Acc:," + xA + "," + yA + "," + zA;
}
if (isGyroscope == true) {
log = log + ",Gyro:," + xGy + "," + yGy + "," + zGy;
}
if (isUncalGyroscope == true) {
log = log + ",UncGyro:," + xGyu + "," + yGyu + "," + zGyu;
}
if (isGravity == true) {
log = log + ",Gravity:," + xGr + "," + yGr + "," + zGr;
}
if (isMagnet == true) {
log = log + ",Mag:," + xMg + "," + yMg + "," + zMg;
}
if (isUncalMagnet == true){
log = log + ",UncMag:," + xMgu + "," + yMgu + "," + zMgu;
}
if (isLinearAcceleration == true) {
log = log + ",Linear acc:," + xLA + "," + yLA + "," + zLA;
}
if (isLight == true){
log = log + ",Light:," + light;
}
if (isTemperature == true) {
log = log + ",Temp:," + temperature;
}
if (isProximity == true){
log = log + ",Proximity:," + proximity;
}
if (isPressure == true){
log = log + ",AirPressure:," + airPressure;
}
if (isHumidity == true){
log = log + ",Humidity:," + humidity;
}
// + ", xA:" + xA + ", yA:" + yA + ", zA:" + zA
//+ ", xG:" + xGy + ", yG:" + yGy + ", zG: " + zGy + ", "
// + ", xGu:" + xGyu + ", yGu:" + yGyu + ", zGu: " + zGyu + ", "
//+ ",Acc:," + xA + "," + yA + "," + zA
// + ",Gyro:," + xGy + "," + yGy + "," + zGy
//+ ",UncGyro:," + xGyu + "," + yGyu + "," + zGyu
//+ ",Temp:," + temperature
//+ ",Gravity:," + xGr + "," + yGr + "," + zGr
//+ ",Light:," + xA + "," + yA + "," + zA
//+ ",Linear acc:," + xLA + "," + yLA + "," + zLA
//+ ",Mag:," + xMg + "," + yMg + "," + zMg
//+ ",UncMag:," + xMgu + "," + yMgu + "," + zMgu
//+ ",Air:," + airPressure
//+ ",Humidity:," + humidity
// + ",Proximity:," + proximity
// log = log + gpsReader.getGpsLog();
//+ common.gpsTime;
log = log + common.gpsLog;
FileCreator file = new FileCreator();
file.write("Logs", log);
}
}
@Override
public void onAccuracyChanged(Sensor sensor, int i) {
//Do nothing
}
// To provide binding for a service, you must implement the onBind() callback method.
// This method returns an IBinder object that defines the programming interface that
// clients can use to interact with the service.
@Override
public IBinder onBind(Intent intent) {
//return mBinder;
return null;
}
@Override
public void onDestroy() {
//Toast.makeText(this, "Service done", Toast.LENGTH_SHORT).show();
mSensorManager.unregisterListener(this);
}
}
全局变量的“Common”类
package com.crowdsourcing.usgs;
import android.app.Application;
/**
* Created by tomokazy on 9/20/14.
*/
public class Common extends Application{
// Global
long initSysTime;
long initGPSTime;
long gpsTime;
String gpsLog;
public void init(){
gpsTime = 0;
gpsLog = "";
}
}