Get location android Kotlin

Question

I recently added get location function. When I try to show longitude and latitude, it returns zero.

This my LocationListener class:

inner class MylocationListener: LocationListener {     constructor():super(){         mylocation= Location("me")         mylocation!!.longitude         mylocation!!.latitude     }      override fun onLocationChanged(location: Location?) {         mylocation=location     }      override fun onStatusChanged(p0: String?, p1: Int, p2: Bundle?) {}      override fun onProviderEnabled(p0: String?) {}      override fun onProviderDisabled(p0: String?) {} } 

And this my GetUserLocation function:

fun GetUserLocation(){     var mylocation= MylocationListener()     var locationManager=getSystemService(Context.LOCATION_SERVICE) as LocationManager     locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,0,0.1f,mylocation) } 

And this my function to return my longitude and latitude:

fun getLoction (view: View){     prgDialog!!.show();      GetUserLocation()      button.setTextColor(getResources().getColor(R.color.green));     textView.text = mylocation!!.latitude.toFloat().toString()     Toast.makeText(this, mylocation!!.latitude.toFloat().toString(), Toast.LENGTH_LONG).show()     Toast.makeText(this, mylocation!!.longitude.toFloat().toString(), Toast.LENGTH_LONG).show()      prgDialog!!.hide() }  

Answer 1

In 2019 Best Offical Solution in Kotlin

Google API Client/FusedLocationApi are deprecated and Location Manager is not useful at all. So Google prefer Fused Location Provider Using the Google Play services location APIs "FusedLocationProviderClient" is used to get location and its better way for battery saving and accuracy

Here is sample code in kotlin to get the last known location /one-time location( equivalent to the current location)

 // declare a global variable of FusedLocationProviderClient     private lateinit var fusedLocationClient: FusedLocationProviderClient  // in onCreate() initialize FusedLocationProviderClient     fusedLocationClient = LocationServices.getFusedLocationProviderClient(context!!)   /**      * call this method for receive location      * get location and give callback when successfully retrieve      * function itself check location permission before access related methods      *      */     fun getLastKnownLocation() {             fusedLocationClient.lastLocation                 .addOnSuccessListener { location->                     if (location != null) {                        // use your location object                         // get latitude , longitude and other info from this                     }                  }      } 

---

If your app can continuously track the location then you have to receive Receive location updates

Check the sample for that in kotlin

// declare a global variable FusedLocationProviderClient         private lateinit var fusedLocationClient: FusedLocationProviderClient      // in onCreate() initialize FusedLocationProviderClient         fusedLocationClient = LocationServices.getFusedLocationProviderClient(context!!)         // globally declare LocationRequest         private lateinit var locationRequest: LocationRequest          // globally declare LocationCallback             private lateinit var locationCallback: LocationCallback           /**          * call this method in onCreate          * onLocationResult call when location is changed           */         private fun getLocationUpdates()         {                  fusedLocationClient = LocationServices.getFusedLocationProviderClient(context!!)                 locationRequest = LocationRequest()                 locationRequest.interval = 50000                 locationRequest.fastestInterval = 50000                 locationRequest.smallestDisplacement = 170f // 170 m = 0.1 mile                 locationRequest.priority = LocationRequest.PRIORITY_HIGH_ACCURACY //set according to your app function                 locationCallback = object : LocationCallback() {                     override fun onLocationResult(locationResult: LocationResult?) {                         locationResult ?: return                          if (locationResult.locations.isNotEmpty()) {                             // get latest location                              val location =                                 locationResult.lastLocation                             // use your location object                             // get latitude , longitude and other info from this                         }                       }                 }         }          //start location updates         private fun startLocationUpdates() {             fusedLocationClient.requestLocationUpdates(                 locationRequest,                 locationCallback,                 null /* Looper */             )         }          // stop location updates         private fun stopLocationUpdates() {             fusedLocationClient.removeLocationUpdates(locationCallback)         }          // stop receiving location update when activity not visible/foreground         override fun onPause() {             super.onPause()             stopLocationUpdates()         }          // start receiving location update when activity  visible/foreground         override fun onResume() {             super.onResume()             startLocationUpdates()         } 

Make sure you take care about Mainfaist permission and runtime permission for location

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

and for Gradle add this

implementation 'com.google.android.gms:play-services-location:17.0.0' 

For more details follow these official documents

https://developer.android.com/training/location/retrieve-current

https://developer.android.com/training/location/receive-location-updates

https://developers.google.com/android/reference/com/google/android/gms/location/FusedLocationProviderClient

Answer 2

When GetUserLocation returns, locationManager goes out of scope and presumably is destroyed, preventing onLocationChanged from being called and providing updates.

Also, you've defined mylocation inside of GetUserLocation so it also goes out of scope and further kills any chance or your getting an update.

You have not shown where and how the outer mylocation is declared (outside of GetUserLocation), but how ever it is declared, it is being shadowed by the one inside of GetUserLocation. So you aren't getting much.

Here is an example of how you might do it. (The variable thetext is defined within the layout xml and accessed with Kotlin extensions.)

// in the android manifest <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/> <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/> // allow these through Appliation Manager if necessary  // inside a basic activity private var locationManager : LocationManager? = null  override fun onCreate(savedInstanceState: Bundle?) {     super.onCreate(savedInstanceState)     setContentView(R.layout.activity_main)     setSupportActionBar(toolbar)      // Create persistent LocationManager reference     locationManager = getSystemService(LOCATION_SERVICE) as LocationManager?      fab.setOnClickListener { view ->         try {             // Request location updates             locationManager?.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0L, 0f, locationListener)         } catch(ex: SecurityException) {             Log.d("myTag", "Security Exception, no location available")         }     } }  //define the listener private val locationListener: LocationListener = object : LocationListener {     override fun onLocationChanged(location: Location) {         thetext.text = ("" + location.longitude + ":" + location.latitude)     }     override fun onStatusChanged(provider: String, status: Int, extras: Bundle) {}     override fun onProviderEnabled(provider: String) {}     override fun onProviderDisabled(provider: String) {} }