IOS mapping - distance between two points

gistfile1.cs

using System;
using CoreGraphics;
using Foundation;
using UIKit;
using MapKit;
using CoreLocation;
using System.Diagnostics;

namespace MappingApp
{
    public partial class MappingAppViewController : UIViewController
    {
		CLLocationManager locationManager = new CLLocationManager();

        public MappingAppViewController(IntPtr handle) : base(handle)
        {
        }

        public override void DidReceiveMemoryWarning()
        {
            // Releases the view if it doesn't have a superview.
            base.DidReceiveMemoryWarning();
			
            // Release any cached data, images, etc that aren't in use.
        }

        #region View lifecycle

        public override void ViewDidLoad()
        {
            base.ViewDidLoad();
			
            // Perform any additional setup after loading the view, typically from a nib.

            // TODO: Step 1a - add the map view
			var map = new MKMapView(this.View.Frame);

			this.View.Add (map);

			map.MapType = MKMapType.Hybrid;

			map.RotateEnabled = true;
			map.ZoomEnabled = true;
			map.PitchEnabled = true;

			if (UIDevice.CurrentDevice.CheckSystemVersion(8, 0) )
				locationManager.RequestWhenInUseAuthorization ();

			map.ShowsUserLocation = true;


            // TODO: Step 1b - change the map style
            // map.MapType = MKMapType.Standard;
            // map.MapType = MKMapType.Satellite;
            // map.MapType = MKMapType.Hybrid;

            // TODO: Step 1c - enable/disable interactions
            // map.ZoomEnabled = false;
            // map.ScrollEnabled = false;

            // TODO: Step 1d - show user location
			// if (UIDevice.CurrentDevice.CheckSystemVersion (8, 0)) {
			// 	 locationManager.RequestWhenInUseAuthorization();
			// }
            // map.ShowsUserLocation = true;

			/*
			CLLocation fromAddress = new CLLocation(FromAddress.lat,FromAddress.lng); 
			CLLocation toAddress = new CLLocation (ToAddress.lat, ToAddress.lng); //ios mapkit distance test. 
			distance = toAddress.DistanceFrom (fromAddress); //google distance test 
			*/


			//pins
			var pointAnnotation = new MKPointAnnotation ();
			pointAnnotation.SetCoordinate (new CLLocationCoordinate2D (37.797530, -122.402590));
			map.AddAnnotation (pointAnnotation);

			pointAnnotation = new MKPointAnnotation ();
			pointAnnotation.SetCoordinate (new CLLocationCoordinate2D (42.374172, -71.120639));
			map.AddAnnotation (pointAnnotation);


			MKDirectionsRequest request = new MKDirectionsRequest ();

			MKPlacemarkAddress placemark = null;

			var orignPlaceMark = new MKPlacemark (new CLLocationCoordinate2D (37.797530, -122.402590), placemark);
			var sourceItem = new MKMapItem(orignPlaceMark);

			//End at Xamarin Cambridge Office
			var destPlaceMark = new MKPlacemark(new CLLocationCoordinate2D(42.374172, -71.120639), placemark);
			var destItem = new MKMapItem(destPlaceMark);

			request.Source = sourceItem;
			request.Destination = destItem;
			request.RequestsAlternateRoutes = true;


			var directions = new MKDirections (request);

			directions.CalculateDirections ((response, error) => {
				if(error != null)
				{
					Console.WriteLine(error.LocalizedDescription);
				}
				else
				{
					foreach (var route in response.Routes)
					{
						map.AddOverlay(route.Polyline);

						Console.WriteLine(route.Name + " " + route.Distance + "(m) " + route.ExpectedTravelTime + "(s)");
					}
				}

			});

			MKDirections dir = new MKDirections ();

			map.Delegate = new MyMapDelegate ();

        }



        public override void ViewWillAppear(bool animated)
        {
            base.ViewWillAppear(animated);
        }

        public override void ViewDidAppear(bool animated)
        {
            base.ViewDidAppear(animated);
        }

        public override void ViewWillDisappear(bool animated)
        {
            base.ViewWillDisappear(animated);
        }

        public override void ViewDidDisappear(bool animated)
        {
            base.ViewDidDisappear(animated);
        }

        #endregion
    }

	// Setup a map delgate to handle annotations and relative eventing
	class MyMapDelegate : MKMapViewDelegate
	{
		MKPolylineRenderer polylineRenderer = null;
		public override MKOverlayRenderer OverlayRenderer(MKMapView mapView, IMKOverlay overlay)
		{
			if (overlay is MKPolyline) 
			{
				if (polylineRenderer == null) 
				{
					polylineRenderer = new MKPolylineRenderer(overlay as MKPolyline);
					polylineRenderer.StrokeColor = UIColor.Green;
				}
				return polylineRenderer;
			} 
			else 
			{
				Debug.WriteLine("OverlayRenderer() - Unknown overlay type!");
				return null;
			}

		}            
	}
}