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

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) {}
}