void mapControl_SelectionChanged(object sender, MapSelectionChangedEventArgs e) { var dataItem = e.Selection.FirstOrDefault() as QuoteMapItem; if (dataItem != null) { Callout.Location = dataItem.Address.ToGeoPoint(); var total = CollectionViewModel.GetOpportunity(ViewModel.Stage, dataItem.Address.City); Callout.Text = string.Format("TOTAL<br><color=206,113,0><b><size=+4>{0:c}</color></size></b><br>{1}", total, dataItem.Address.City); } }