v2.0 - Setting extent with projection on map with bound layers throwing exception.

BrandonCopeland — Mon, 03 May 2010 16:30:45 GMT

Just updated updated to v2.0 and encountering exception when trying to set the spatial reference and extent on map with layers set via data binding. Any suggestions?

Exception...

{System.Windows.Markup.XamlParseException: Set property 'ESRI.ArcGIS.Client.Map.Extent' threw an exception. [Line: 89 Position: 85] ---> System.NullReferenceException: Object reference not set to an instance of an object.
   at ESRI.ArcGIS.Client.Map.getSpatialReferenceFromLayers()
   at ESRI.ArcGIS.Client.Map.get_SpatialReference()
   at ESRI.ArcGIS.Client.Map.set_Extent(Envelope value)
   --- End of inner exception stack trace ---
   at System.Windows.Application.LoadComponent(Object component, Uri resourceLocator)
   at LJA.Client.RCP.QBMapFull.MapModule.MapView.InitializeComponent()
   at LJA.Client.RCP.QBMapFull.MapModule.MapView..ctor()}

<esri:Envelope x:Key="InitialExtent" XMax="-10539988" XMin="-10681703" YMax="3541573" YMin="3405056">
    <esri:Envelope.SpatialReference>
        <esri:SpatialReference WKID="102113"/>
    </esri:Envelope.SpatialReference>
</esri:Envelope>

<esri:Map x:Name="TheMap" Layers="{Binding Layers, Mode=OneWay}" Extent="{StaticResource InitialExtent}">
</esri:Map>

On view model...

public LayerCollection Layers
{
    get { return _layers ?? (_layers = new LayerCollection()); }
    set
    {
        if (value == _layers) return;

        _layers = value;
        OnPropertyChanged("Layers");
    }
}

Re: v2.0 - Setting extent with projection on map with bound layers throwing exception

DominiqueBroux — Sat, 11 Dec 2021 07:19:40 GMT

You are right, it looks like there is an issue in this case.

As a temporarly workaround, you can initialize the extent by code when the map is loaded :

       <esri:Map x:Name="MyMap" Layers="{Binding Layers, Mode=OneWay}" Loaded="MyMap_Loaded" />

 void MyMap_Loaded(object sender, System.Windows.RoutedEventArgs e)
 {
  MyMap.Extent = (ESRI.ArcGIS.Client.Geometry.Envelope)LayoutRoot.Resources["InitialExtent"];
 }

/Dominique

topic v2.0 - Setting extent with projection on map with bound layers throwing exception. in ArcGIS API for Silverlight Questions

v2.0 - Setting extent with projection on map with bound layers throwing exception.

Re: v2.0 - Setting extent with projection on map with bound layers throwing exception