Retrieving Last Location on Simulator in Android?

Question

I'm trying to get last location, but it always fails, here's my code:

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
    <TextView
        android:id="@+id/tv1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="hello" />
</LinearLayout>

MainActivity.java

package com.example.gps;

import android.app.Activity;
import android.content.Context;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.widget.TextView;

public class MainActivity extends Activity {

    LocationManager mLocationManager;
    TextView tv;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.tv1);
        mLocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        Criteria criteria = new Criteria();
        criteria.setAccuracy(Criteria.ACCURACY_FINE);
        criteria.setPowerRequirement(Criteria.POWER_LOW);
        String locationprovider = mLocationManager.getBestProvider(criteria, true);
        Location mLocation = mLocationManager.getLastKnownLocation(locationprovider);
        tv.setText("Last location lat:" + mLocation.getLatitude() + " long:" + mLocation.getLongitude());
    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.gps"
    android:versionCode="1"
    android:versionName="1.0" >

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

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

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.gps.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>

I've sent coordinates via DDMS/emulator control window, as in next image:

And the GPS hardware is enabled for my AVD as you may see in AVD details (hw.gps): enter image description here

And location access is enabled in emulator as you may see: enter image description here

I also tried to send coordinates via telnet, using commands:

telnet localhost 5556 
geo fix 13.24 52.31

But unfortunately, getLastKnownLocation() method always returns null!
How to solve this ?

score 0 · Answer 1 · answered Jan 09 '13 at 12:26

0

Change your code like this

if(locationprovider!=null)
{
 Location mLocation = mLocationManager.getLastKnownLocation(locationprovider);
}
else
{
locationprovider =LocationManager.GPS_PROVIDER;
 Location mLocation = mLocationManager.getLastKnownLocation(locationprovider);
}

answered Jan 09 '13 at 12:26

TNR

5,839
3
33
62

I tried your solution, the code entered the 'if block' with locationprovider = "gps", and same problem exists (i.e. mLocation is null) :( – Ashraf Bashir Jan 09 '13 at 12:32
Thanks for your try to help, you may check the problem/solution in my answer :) – Ashraf Bashir Jan 09 '13 at 13:14

score 0 · Accepted Answer · answered Jan 09 '13 at 13:10

For those who are interested, I found the problem & solution :)
It's because the emulator never retrieved a location before, so last location is always null !
To avoid this, we have to get the location at least once, using this code:

public class MainActivity extends Activity implements LocationListener {
    LocationManager mLocationManager;
    TextView tv;
    Location mLocation;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.tv1);
        mLocationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        Criteria criteria = new Criteria();
        criteria.setAccuracy(Criteria.ACCURACY_FINE);
        criteria.setPowerRequirement(Criteria.POWER_LOW);
        String locationprovider = mLocationManager.getBestProvider(criteria, true);
        mLocationManager.requestLocationUpdates(locationprovider, 5000, (float) 2.0, this);
    }

    @Override
    public void onLocationChanged(Location location) {
        mLocation = location;
        showupdate();
    }

    public void onProviderDisabled(String arg0) {
    }

    public void onProviderEnabled(String provider) {
    }

    public void onStatusChanged(String a, int b, Bundle c) {
    }

    public void showupdate() {
        tv.setText("Last location lat:" + mLocation.getLatitude() + " long:" + mLocation.getLongitude());
    }
}

Then whenever the initial code posted in the question was run, it will execute correctly :)

score 0 · Answer 3 · answered Jan 09 '13 at 13:11

0

in emulator you wont have any support for GPS .. it will work simply if we will pass the co-ordinates.. Thats it . in emulator we can stimulate fake gps location to test it . we cannot expect the last location from that..

answered Jan 09 '13 at 13:11

itsrajesh4uguys

4,610
3
20
31

score 0 · Answer 4 · answered Jan 09 '13 at 13:26

I guess you are missing the internet permissions:

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

and seems that You are using the default emulator for android but you should use Google API and set some coordinates for your Geopoint in first place.

Retrieving Last Location on Simulator in Android?

4 Answers4