Best way to extend Bing Maps for Metro functionality

Question

Hi, I am looking to extend the functionality of the Bing Maps for Metro control.  In particular, I would like to add:

• Support for collections of Pushpins, i.e. if there are thousands, only add those 'in view' to the map layer.
• Support for 'callouts' to appear when pushpins are clicked.

To accomplish this, I tried sublassing Map, but you have sealed the class - is this intentional?  Therefore, what is the best way to extend the functionality?  I have begun something like the code below; is this a good way to go?  Or do you foresee problems with this approach?

    public class MapManager
    {

        // Private Members
        private Map map;
        AnnotationManager annotationManager;

        public MapManager(Map _map)
        {
            this.map = _map;
            annotationManager = new AnnotationManager(this.map);
        }

        public void addAnnotations(IEnumerable<IMapAnnotation> annotations)
        {
            annotationManager.addAnnotations(annotations);
        }
        public void removeAnnotations(IEnumerable<IMapAnnotation> annotations)
        {
            annotationManager.removeAnnotations(annotations);
        }
    }





internal class AnnotationManager
    {

        // Private members
        Map map;
        MapLayer annotationsLayer;
        Dictionary<IMapAnnotation, Pushpin> pins;
        AnnotationCollection annotationCollection;

        public AnnotationManager(Map map)
        {
            // Map
            this.map = map;

            // Collection to hold the annotation objects
            annotationCollection = new AnnotationCollection();
            annotationCollection.AnnotationsChanged += annotationCollection_AnnotationsChanged;

            // Layer to hold the annotations
            annotationsLayer = new MapLayer();
            map.Children.Add(annotationsLayer);

            // Pushpins to represent the annotations
            pins = new Dictionary<IMapAnnotation, Pushpin>();
        }

        // Public Methods
        public void addAnnotations(IEnumerable<IMapAnnotation> annotations)
        {
            annotationCollection.addAnnotations(annotations);
        }
        public void removeAnnotations(IEnumerable<IMapAnnotation> annotations)
        {
            annotationCollection.addAnnotations(annotations);
        }

        // Incoming event - Annotations Changed
        void annotationCollection_AnnotationsChanged(object sender, AnnotationCollectionChangedEventArgs e)
        {
            foreach (IMapAnnotation item in e.annotationsAdded)
            {
                Pushpin newPin = new Pushpin();
                newPin.Text = item.Title();

                Bing.Maps.Location loc = new Bing.Maps.Location(item.Latitude(), item.Longitude() );
                MapLayer.SetPosition(newPin, loc);

                pins.Add(item, newPin);
                annotationsLayer.Children.Add(newPin);
            }
            foreach (IMapAnnotation item in e.annotationsRemoved)
            {
                Pushpin oldPin;
                if (pins.TryGetValue(item, out oldPin))
                {
                    annotationsLayer.Children.Remove(oldPin);
                    pins.Remove(item);
                }
            }
        }





    public interface IMapAnnotation
    {
        string Title() ;
        string Subtitle();
        double Longitude();
        double Latitude();

    }

Comments very welcome.

---

_______________________________ Carl Partridge

Answer 1

Hi Carl,

I'm not an expert on the topic and experts can respond better but there was a similar discussion underway on the same forum regarding clustering of pushpin. This might help (to show only handful of puspins at a particular instant),

http://www.scottlogic.co.uk/blog/colin/2011/11/pushpin-clustering-with-the-windows-phone-7-bing-map-control/

Also, if I understand correctly any user control can be used in place of pushpin which means you can have a user defined control encapsulating the logic of custom popup.