Boris Pawlowski Boris Pawlowski - 6 months ago 61
Android Question

How to get current location in Android

I'm having troubles of getting my current position coordinates using the NETWORK provider of android location system.

Already read a lot of tutorials and implemented 4 or 5 existing classes to my project and all of them are giving me the last coordinates but not the current ones.

I'm pretty sure that the problem is something fundamental that I am missing but I am not able to understand what exactly it is.

Codes i'm using now:
This is my main Activity

package com.example.locationtests;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.TextView;

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
GPSTracker mGPS = new GPSTracker(this);

TextView text = (TextView) findViewById(R.id.texts);
if(mGPS.canGetLocation ){
mGPS.getLocation();
text.setText("Lat"+mGPS.getLatitude()+"Lon"+mGPS.getLongitude());
}else{
text.setText("Unabletofind");
System.out.println("Unable");
}
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}


}

This is the class im using for Tracking:

package com.example.locationtests;

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.provider.Settings;
import android.util.Log;

public final class GPSTracker implements LocationListener {

private final Context mContext;

// flag for GPS status
public boolean isGPSEnabled = false;

// flag for network status
boolean isNetworkEnabled = false;

// flag for GPS status
boolean canGetLocation = false;

Location location; // location
double latitude; // latitude
double longitude; // longitude

// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 1; // 10 meters

// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1; // 1 minute

// Declaring a Location Manager
protected LocationManager locationManager;

public GPSTracker(Context context) {
this.mContext = context;
getLocation();
}

/**
* Function to get the user's current location
*
* @return
*/
public Location getLocation() {
try {
locationManager = (LocationManager) mContext
.getSystemService(Context.LOCATION_SERVICE);

// getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);

Log.v("isGPSEnabled", "=" + isGPSEnabled);

// getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

Log.v("isNetworkEnabled", "=" + isNetworkEnabled);

if (isGPSEnabled == false && isNetworkEnabled == false) {
// no network provider is enabled
} else {
this.canGetLocation = true;
if (isNetworkEnabled) {
location=null;
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled) {
location=null;
if (location == null) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS Enabled", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}

} catch (Exception e) {
e.printStackTrace();
}

return location;
}

/**
* Stop using GPS listener Calling this function will stop using GPS in your
* app
* */
public void stopUsingGPS() {
if (locationManager != null) {
locationManager.removeUpdates(GPSTracker.this);
}
}

/**
* Function to get latitude
* */
public double getLatitude() {
if (location != null) {
latitude = location.getLatitude();
}

// return latitude
return latitude;
}

/**
* Function to get longitude
* */
public double getLongitude() {
if (location != null) {
longitude = location.getLongitude();
}

// return longitude
return longitude;
}

/**
* Function to check GPS/wifi enabled
*
* @return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}

/**
* Function to show settings alert dialog On pressing Settings button will
* lauch Settings Options
* */
public void showSettingsAlert() {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);

// Setting Dialog Title
alertDialog.setTitle("GPS is settings");

// Setting Dialog Message
alertDialog
.setMessage("GPS is not enabled. Do you want to go to settings menu?");

// On pressing Settings button
alertDialog.setPositiveButton("Settings",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent(
Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});

// on pressing cancel button
alertDialog.setNegativeButton("Cancel",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});

// Showing Alert Message
alertDialog.show();
}

@Override
public void onLocationChanged(Location location) {
}

@Override
public void onProviderDisabled(String provider) {
}

@Override
public void onProviderEnabled(String provider) {
}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}

}


This is my AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.locationtests"
android:versionCode="1"
android:versionName="1.0" >
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.VIBRATE" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.location" android:required="true" />
<uses-feature android:name="android.hardware.location.gps" android:required="false" />

<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.locationtests.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

</manifest>


Acctualy GPS possitioning works fine, but NETWORK positioning dosn't.
When Ive turned devices GPS on cordinates keep changing while im moving, but dosnt happence same when I have turn it off and relay on the NETWORK_PROVIDER

Answer

First you need to define a LocationListener to handle location changes.

private final LocationListener mLocationListener = new LocationListener() {
    @Override
    public void onLocationChanged(final Location location) {
        //your code here
    }
};

Then get the LocationManager and ask for location updates

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    mLocationManager = (LocationManager) getSystemService(LOCATION_SERVICE);

    mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, LOCATION_REFRESH_TIME,
            LOCATION_REFRESH_DISTANCE, mLocationListener);
}

And finally make sure that you have added the permission on the Manifest,

For using only network based location use this one

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

For GPS based location, this one

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>