gps.txt

// permission

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


//layout

  <TextView
        android:layout_width="fill_parent"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:layout_height="wrap_content"
        android:text="Location (when available)"
        android:id="@+id/location_text"
        android:layout_marginBottom="15dp" />
 
    <TextView
        android:layout_width="fill_parent"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:layout_height="wrap_content"
        android:text="Address (when available)"
        android:id="@+id/address_text"
        android:layout_marginTop="10dp" />

//code
  public class MainActivity : Activity, ILocationListener
    {
        static readonly string TAG = "X:" + typeof(MainActivity).Name;
        TextView _addressText;
        Location _currentLocation;
        LocationManager _locationManager;

        string _locationProvider;
        TextView _locationText;
          protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.Main);


            _addressText = FindViewById<TextView>(Resource.Id.address_text);
            _locationText = FindViewById<TextView>(Resource.Id.location_text);
        
            InitializeLocationManager();

        }

        void InitializeLocationManager()
        {
            _locationManager = (LocationManager)GetSystemService(LocationService);
            Criteria criteriaForLocationService = new Criteria
            {
                Accuracy = Accuracy.Fine
            };
            IList<string> acceptableLocationProviders = _locationManager.GetProviders(criteriaForLocationService, true);

            if (acceptableLocationProviders.Any())
            {
                _locationProvider = acceptableLocationProviders.First();
            }
            else
            {
                _locationProvider = string.Empty;
            }
            Log.Debug(TAG, "Using " + _locationProvider + ".");
        }
       
        async Task<Address> ReverseGeocodeCurrentLocation()
        {
            Geocoder geocoder = new Geocoder(this);
            IList<Address> addressList =
                await geocoder.GetFromLocationAsync(_currentLocation.Latitude, _currentLocation.Longitude, 10);

            Address address = addressList.FirstOrDefault();
            return address;
        }

        void DisplayAddress(Address address)
        {
            if (address != null)
            {
                StringBuilder deviceAddress = new StringBuilder();
                for (int i = 0; i < address.MaxAddressLineIndex; i++)
                {
                    deviceAddress.Append(address.GetAddressLine(i));
                }
                // Remove the last comma from the end of the address.
                _addressText.Text = deviceAddress.ToString();
            }
            else
            {
                _addressText.Text = "Unable to determine the address. Try again in a few minutes.";
            }
        }

        // removed code for clarity

        public void OnProviderDisabled(string provider) { }

        public void OnProviderEnabled(string provider) { }

        public void OnStatusChanged(string provider, Availability status, Bundle extras) { }

        public async void OnLocationChanged(Location location)
        {
            _currentLocation = location;
            if (_currentLocation == null)
            {
                _locationText.Text = "Unable to determine your location. Try again in a short while.";
            }
            else
            {
                _locationText.Text = string.Format("{0:f6},{1:f6}", _currentLocation.Latitude, _currentLocation.Longitude);
                Address address = await ReverseGeocodeCurrentLocation();
                DisplayAddress(address);
            }
        }
        protected override void OnResume()
        {
            base.OnResume();
            _locationManager.RequestLocationUpdates(_locationProvider, 0, 0, this);
        }
        protected override void OnPause()
        {
            base.OnPause();
            _locationManager.RemoveUpdates(this);
        }
    }