Zoom in KM distance

LakshmananVenkatesan

Hi All

I want to show the zoom in distance in KM whenever user zooms in/out in my status bar. How do I go about. Please give me if I have some samples

SR

JenniferNery

You can listen to map's ExtentChanged event and use GeometryService Distance (see sample http://help.arcgis.com/en/webapi/silverlight/samples/start.htm#Distance)

In the following code, I used only one MapPoint from each extent, the upper right corner, so I calculate the distance from the upper right corner of previous extent with the upper right corner of the new extent.

 public MainPage()
        {
            InitializeComponent();
            this.MyMap.ExtentChanged += new EventHandler<ExtentEventArgs>(MyMap_ExtentChanged);
            gs = new GeometryService("http://sampleserver3.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer");
            gs.DistanceCompleted += new EventHandler<DistanceEventArgs>(gs_DistanceCompleted);
        }

        void gs_DistanceCompleted(object sender, DistanceEventArgs e)
        {
            double distanceInKm = e.Distance;
        }

        GeometryService gs;
     
        void MyMap_ExtentChanged(object sender, ExtentEventArgs e)
        {
            if (e.OldExtent !=null && e.NewExtent != null)
            {
                gs.DistanceAsync(GetMapPoint(e.OldExtent), GetMapPoint(e.NewExtent), new DistanceParameters()
                {
                    DistanceUnit = LinearUnit.Kilometer,
                    Geodesic = true
                });                
            }
        }

        private MapPoint GetMapPoint(Envelope extent)
        {
            return new MapPoint() { SpatialReference = this.MyMap.SpatialReference, X = extent.XMax, Y = extent.YMax };
        }

Jennifer