mLastLocation value is getting null while creating Android Location API using GPS

Question

I'm trying to create an Android Location API using Google Play Services. But I keep on getting " mLastLocation value as null " with a message " Couldn't get the location. Make sure location is enabled on the device " which I have given to display for the null value of mLastLocation. Can anyone tell me what I am doing wrong? Here's the code which I have been trying. Thanks in Advance.

CODE:

package com.example.jamshi.locationapi;

import android.app.Activity;
import android.location.Location;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.GoogleApiClient.ConnectionCallbacks;
import com.google.android.gms.common.api.GoogleApiClient.OnConnectionFailedListener;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;

 public class MainActivity extends Activity implements ConnectionCallbacks,OnConnectionFailedListener {

    private static final String TAG = MainActivity.class.getSimpleName();
    private static final int PLAY_SERVICES_RESOLUTION_REQUEST = 1000;
    private Location mLastLocation;
    private GoogleApiClient mGoogleApiClient;

    private TextView tvLocation;
    private Button btnShowLocation,btnLocationUpdates;


    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        tvLocation = (TextView) findViewById(R.id.tvLocation);
        btnShowLocation = (Button) findViewById(R.id.btnShowLocation);
        btnLocationUpdates = (Button) findViewById(R.id.btnLocationUpdates);

        if(checkPlayServices()){
            buildGoogleApiClient();
        }

        btnShowLocation.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                displayLocation();
            }
        });

    }

    private void displayLocation() {

        mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
        if (mLastLocation != null) {
            double latitude = mLastLocation.getLatitude();
            double longitude = mLastLocation.getLongitude();
            tvLocation.setText(latitude + ", " + longitude);

        } else {

            tvLocation.setText("(Couldn't get the location. Make sure location is enabled on the device)");
        }
    }

    private boolean checkPlayServices(){

        int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
        if(resultCode != ConnectionResult.SUCCESS){
            if(GooglePlayServicesUtil.isUserRecoverableError(resultCode)){
                GooglePlayServicesUtil.getErrorDialog(resultCode,this,PLAY_SERVICES_RESOLUTION_REQUEST).show();
            }else{
                Toast.makeText(getApplicationContext(),"This device is not supported",Toast.LENGTH_LONG).show();
                finish();
            }
            return false;
        }
        return true;
    }

    protected synchronized void buildGoogleApiClient() {

        if (mGoogleApiClient == null) {
            mGoogleApiClient = new GoogleApiClient.Builder(this)
                    .addConnectionCallbacks(this)
                    .addOnConnectionFailedListener(this)
                    .addApi(LocationServices.API).build();
        }
    }

    @Override
    protected void onStart() {

        if (mGoogleApiClient != null) {
            mGoogleApiClient.connect();
        }
        super.onStart();
    }

    @Override
    protected void onResume() {

        super.onResume();
        checkPlayServices();
    }


    @Override
    public void onConnectionFailed(ConnectionResult result) {

        Log.i(TAG, "Connection failed: ConnectionResult.getErrorCode() = "
                + result.getErrorCode());
    }

    @Override
    public void onConnected(Bundle arg0) {

        displayLocation();
    }

    @Override
    public void onConnectionSuspended(int arg0)
    {
        mGoogleApiClient.connect();
    }

}

Answer 1

如果您在模拟器上运行，请先打开谷歌地图应用程序，然后尝试使用您的应用程序

Answer 2

Test in device if you want to get data in first time and for genymotion emulator set location from side menus and then try. and if you are using android studio emulator set mock location and then try.

For more check this - How to emulate GPS location in the Android Emulator?