Hi,I am fairly new to using ArcGIS mapping in Silverlight and am having a few issues that I'm hoping someone can help point me in the right direction.Problem 1. I have been struggling like crazy to get binding to work with anything in the esri:Map. I tried binding the Layers like so<esri:Map x:Name="MyMap" Layers="{Binding VisibleLayers}" />
Then in my ViewModel I have public ObservableCollection<Layer> VisibleLayers
{
get
{
if(_visibleLayers == null)
_visibleLayers = new ObservableCollection<Layer>();
return _visibleLayers;
}
set { _visibleLayers = value; OnPropertyChanged("VisibleLayers"); }
}
It is not a DataContext problem because I have several text boxes and labels binding just fine to the same viewModel. So in the ViewModel's Constructor I have the following:ArcGISTiledMapServiceLayer arcgisLayer = new ArcGISTiledMapServiceLayer();
arcgisLayer.Url = "http://services.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer";
VisibleLayers.Add(arcgisLayer);
Now if I just put this Layer int he XAML it works fine, but that is not my goal. I have 15 or more layers that I need to have the ability to add to VisibleLayers on Demand and I don't want this all done in the code behind. Any Suggestions would be GREATLY Appreciated?Problem 2: I have tried 5 or 6 different means to maintain the Map Extents and selected Graphics through Binding, but am failing miserable. It appears that in the code behind I can create an Envelope and assign the Map's extent to the envelope. However, if I do:<esri:Map x:Name="MyMap" Extent="{Binding MapEnvelope}" />
and in viewModel I have public Envelope MapEnvelope
{
get { return _mapEnvelope; }
set { _mapEnvelope = value; OnPropertyChanged("MapEnvelope"); }
}
However, I always get an error on InitilizeComponents because of the MapExtent binding. I have also tried setting the return value to _mapEnvelope.Extent, but that didn't work either. I have tried creating a converter like so:<esri:Map x:Name="MyMap" Extent="{Binding MapEnvelope, Conveter={StaticResource EnvelopeToExtentConverter}" />
and then in my converter class I have:
namespace MyNamespace.Converters
{
public class EnvelopeToExtentsConverter<T> : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
if (value != null)
return (((Envelope)value).XMin + "," + ((Envelope)value).XMax + "," + ((Envelope)value).YMin + "," + ((Envelope)value).YMax);
else
return null;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
return null; // fix later if get works
}
}
public class MapToExtentsConverter : EnvelopeToExtentsConverter<Envelope> { }
}
and this still gives the same error, I never even get into the converter with a break point so it isn't getting this far. I have also tried this: <esri:Map x:Name="MyMap" >
<esri:Map.Extent>
<esri:Envelope XMax="{Binding MapExtentXMin}" XMin="{Binding MapExtentXMax}" YMax="{Binding MapExtentYMin}" YMin="{Binding MapExtentYMax}" />
</esri:Map.Extent>
</esri:Map>
and in the viewModel had a double for everyone of these properties and that didn't work either.I have also tried binding to a String in the viewModel to maintain the extents and am suffering to a losing battle. I finally ending up cheating by firing a generic EventArgs<myMap> to the viewModel that listens, grabs the map, creates a duplicate in the viewModel. Then on MapLoad I fire it again to the viewModel to recieve it's Map Attributes from the duplicate. This is sloppy and not the correct way to do it. I'm making a wizard that they can come to and from this map page and change selections and I don't want a fresh map everytime they get here, and I DO NOT want to keep views alive after I have left it.Any suggestions???Thanks very much for any feedback.Sam
