topic GraphicsLayer for selected Feature in ArcGIS API for Silverlight Questions

GraphicsLayer for selected Feature

UlfGrimhardt — Wed, 11 Aug 2010 12:11:11 GMT

Hi,

I have a ComboBox which shows the Names of some Features in my Layer.
Now i would like to higlight the selected Feature with a red dot, so i need to add a graphics layer to it right?

My Question is, how can i get the Feature to add it to the GraphicsLayer?
Is the FindTask or QueryTask the only way? Can't i just say something like GraphicsLayer.Graphics.add(FeatureID)?

Re: GraphicsLayer for selected Feature

JenniferNery — Wed, 11 Aug 2010 13:32:37 GMT

I think it would be easiest if your ComboBox ItemSource is bound to the FeatureLayer's graphics, that way when a feature name is selected, you can get the graphic from ComboBox selection and add it to a GraphicsLayer.

Something like:
<ComboBox ItemSource={Binding ElementName=MyMap, Path=Layers[FeatureLayerID].Graphics >
<ComboBox.ItemTemplate>
<DataTemplate>
<TextBox Text={Binding Attributes[Name]>...

Subscribe to the ComboBox SelectionChanged event and add this graphic to your GraphicsLayer. Your GraphicsLayer can be defined with a SimpleRenderer that has SimpleMarkerSymbol (Circle, Red) so you would only need to add graphic in code without worrying about its symbol.

Jennifer

Re: GraphicsLayer for selected Feature

TonyBacon — Wed, 11 Aug 2010 16:13:08 GMT

Check this sample out, it uses a mouse over events for the data rows in a grid and also the graphics in a feature layer to highlight a feature and its data row. http://resources.esri.com/help/9.3/arcgisserver/apis/silverlight/samples/start.htm#SpatialQuery

Re: GraphicsLayer for selected Feature

UlfGrimhardt — Thu, 12 Aug 2010 06:38:21 GMT

Thanks for your replies!

I tried this:

<ComboBox Grid.ColumnSpan="2" Margin="4,6" Name="ms_detail_combo" Grid.Column="2" Grid.Row="1" ItemsSource="{Binding ElementName=map, Path=Layers.[0].Graphics}" IsEnabled="False">
<ComboBox.ItemTemplate>
<DataTemplate>
<TextBox Text="{Binding [Messstelle]}"></TextBox>
</DataTemplate>
</ComboBox.ItemTemplate>
</ComboBox>

But my ComboBox doesnt show any Items. I think the Path of my ItemSource is wrong, but iam not quiet sure.
I have a MXD with two Features, and i want to show the Attributes of the first Feature. So my ArcGISDynamicMapServiceLayer is the only Layer i got, but dont i have to set the Sublayer (My first Feature that has Attriubute Messsstelle) as ItemSource? How can i do that in XAML?

Re: GraphicsLayer for selected Feature

JenniferNery — Fri, 13 Aug 2010 03:01:09 GMT

Since you are using ArcGISDynamicMapServiceLayer, it's Layers will be loaded after it has been initialized. So you need to set your ComboBox ItemSource property in code-behind inside your Intialized eventhandler.