Can't get latitude and Longitude

Question

I tried to get latitude and longitude for current location. However, when I use the code below, the location listener is not triggered at all. I've added the LOCATION permission in manifest file.

anyone can help?

Here is the java code:

package com.example.setlocaction;


import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.util.Log;
import android.widget.Toast;

public class MainActivity extends Activity{
double latitude, longitude, radius;
LocationManager mlocManager;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    // Acquire a reference to the system Location Manager 
    mlocManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);  
    // Define a listener that responds to location updates 
    LocationListener locationListener = new LocationListener() 
    {     
        public void onLocationChanged(Location loc) 
        {      
            // Called when a new location is found by the network location provider.       
            Log.i("loc","location changed");
            if (loc!=null)
            {
                loc.getLatitude(); 
                loc.getLongitude(); 
                String Text = "My current location is: " + 
                "Latitud =" + loc.getLatitude() + 
                "Longitud = " + loc.getLongitude(); 
                Toast.makeText( getApplicationContext(),Text,Toast.LENGTH_SHORT).show(); 

            }
        }      
        public void onStatusChanged(String provider, int status, Bundle extras) 
        {}      
        public void onProviderEnabled(String provider) 
        {}      
        public void onProviderDisabled(String provider) 
        {}   
    };              

    Criteria criteria = new Criteria();
        criteria.setAccuracy(Criteria.ACCURACY_FINE);  
        // 高精度  
        criteria.setAltitudeRequired(false);  
        criteria.setBearingRequired(false);  
        criteria.setCostAllowed(true);   
        criteria.setPowerRequirement(Criteria.POWER_LOW);  
        String provider = mlocManager.getBestProvider(criteria, true);
    mlocManager.requestLocationUpdates(provider, 2000, 0, locationListener); 
    Location loc=mlocManager.getLastKnownLocation(provider);
    if (loc==null)
    {
        Log.i("loc","loc=null");
    }
}

}

mafinest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.setlocaction"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
    android:minSdkVersion="7"
    android:targetSdkVersion="17" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.CALL_PHONE" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.RESTART_PACKAGES" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name="com.example.setlocaction.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>

Answer 1

Add following code to your java file

private void GetLocation() 
            {
                LocationDetail pref_LocationDetail = new LocationDetail(_context);
                locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

                if(objCommon.isOnline(_context)) 
                {
                    if(locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER))
                    {
                        locationManager.requestLocationUpdates(
                                LocationManager.NETWORK_PROVIDER , 
                                MINIMUM_TIME_BETWEEN_UPDATES,
                                MINIMUM_DISTANCE_CHANGE_FOR_UPDATES, 
                                new MyLocationListener()    
                                );

                        return ; 
                    }
                    else if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER))
                    {
                        locationManager.requestLocationUpdates(
                                LocationManager.GPS_PROVIDER , 
                                MINIMUM_TIME_BETWEEN_UPDATES,
                                MINIMUM_DISTANCE_CHANGE_FOR_UPDATES, 
                                new MyLocationListener()    
                                );

                        return ;
                    }
                }
            }

            private class MyLocationListener implements LocationListener 
            {

                public void onLocationChanged(Location location) 
                {
                    LocationDetail pref_LocationDetail = new LocationDetail(_context);


                        double Lattitude = location.getLatitude(); 
                        double Longitude =  location.getLongitude();



                    Toast.makeText(_context  , location.getProvider().toString() , Toast.LENGTH_LONG).show();

                    locationManager.removeUpdates(this);  
                    locationManager = null;                                                                                            
                }

                public void onStatusChanged(String s, int i, Bundle b) {
                    Toast.makeText(_context , "Provider status changed",  
                            Toast.LENGTH_LONG).show();   
                }

                public void onProviderDisabled(String s) {
                    Toast.makeText(_context ,
                            "Provider disabled by the user. GPS  turned off",
                            Toast.LENGTH_LONG).show();     
                }

                public void onProviderEnabled(String s) {    
                    Toast.makeText(_context ,
                            "Provider enabled by the user. GPS turned on", 
                            Toast.LENGTH_LONG).show();
                }
            }

just add following code in your manifest

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

Answer 2

try this

  public class MyLocationActivity extends Activity implements LocationListener {
        private LocationManager mgr;
        private String best;
        public static double myLocationLatitude;
        public static double myLocationLongitude;

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

            mgr = (LocationManager) getSystemService(LOCATION_SERVICE);

            dumpProviders();

            Criteria criteria = new Criteria();

            best = mgr.getBestProvider(criteria, true);
            Log.d("best provider", best);

            Location location = mgr.getLastKnownLocation(best);
            dumpLocation(location);

                //may be some intent here
        }

        public void onLocationChanged(Location location) {
            // TODO Auto-generated method stub
            dumpLocation(location);

        }

        public void onProviderDisabled(String provider) {
            // TODO Auto-generated method stub

        }

        public void onProviderEnabled(String provider) {
            // TODO Auto-generated method stub

        }

        public void onStatusChanged(String provider, int status, Bundle extras) {
            // TODO Auto-generated method stub

        }

        @Override
        protected void onPause() {

            super.onPause();
            mgr.removeUpdates(this);
        }

        @Override
        protected void onResume() {

            super.onResume();
            mgr.requestLocationUpdates(best, 15000, 1, this);
        }

        private void dumpLocation(Location l) {

            if (l == null) {

                myLocationLatitude = 0.0;
                myLocationLongitude = 0.0;
            } else {

                myLocationLatitude = l.getLatitude();
                myLocationLongitude = l.getLongitude();
            }
        }

        private void dumpProviders() {

            List<String> providers = mgr.getAllProviders();
            for (String p : providers) {

                dumpProviders(p);
            }
        }

        private void dumpProviders(String s) {

            LocationProvider info = mgr.getProvider(s);
            StringBuilder builder = new StringBuilder();
            builder.append("name: ").append(info.getName());
        }

    }

Answer 3

First of all, your current solution utilizes "getLastKnownLocation" which means, that if you actually retrieve the longitude and latitude, you cannot be certain that it will return the current position of the user. It simply returns the location which was last found which can be miles away.

That is nothing wrong in doing so, but it leaves for uncertainty.

Instead, I have personally implemented a location manager for retrieving the current position of the user by utilizing the code provided in the following post which works great:

https://stackoverflow.com/a/17290348/2399772

By using this specific code, you will also be given the advantage that it tries to utilize the WiFi connection first for determining the position which is slightly better. It that doesn't work, it will utilize the GPS instead. Additionally, if GPS services aren't enabled, a dialogue will be shown telling the user to enable those.

Hope this helps.

Additional notes As I have stated in a previous post, the Geolocation API will does unfortunately not work on all devices. You can hereby consider using the Reverse Geocoding API instead, which is additionally much more reliable:

https://developers.google.com/maps/documentation/geocoding/

It simply requires that you send a HTTP request which should contain latitude and longitude, whereafter it will provide a response in JSON which is easily parsed.

Answer 4

Sometimes it takes a while for the device to deliver the first locations if you haven't used the GPS before. Also, make sure you're in a location where you can gps updates, or try on the emulator using geo fix via telnet.