2.1 RC: Unable to put Behavior on Button in DataTemplate of Legend

Question

I'm unable to put the Spatial Query button from the Graphics Action Behaviors sample onto the Datatemplate of the Legend from this sample.

Is this possible?

Cross posted: http://gis.stackexchange.com/questions/4199/how-to-use-button-with-behavior-in-silverlight-legend

Thanks, Kirk

DominiqueBroux · Answer

Hi Kirk, I tried to debug your code: and, as Jennifer mentionned, I confirm that the TargetName can't be resolved inside a datatemplate (and it's not a legend issue nor an ESRI issue). The TargetObject of the action is always null. In complement to the solution by code given by Jennifer, you might also create your own action which would initialize the Url and the map. Example of an action deriving fom SpatialQueryAction :public class LegendSpatialQueryAction : SpatialQueryAction { protected override void Invoke(object parameter) { var frameWorkElement = AssociatedObject as FrameworkElement; var layerItem = (frameWorkElement == null ? null : frameWorkElement.DataContext as LayerItemViewModel); var dynamicLayer = (layerItem == null ? null : layerItem.Layer as ArcGISDynamicMapServiceLayer); var map = TargetObject as Map; TargetObject = null; // reset in order to send OnTargetChanged if (dynamicLayer != null && map != null) { if (layerItem.LayerType.Contains("MapLayer")) { } // TODO : decide what to do when action is called on map service layer item Url = dynamicLayer.Url + "/" + layerItem.SubLayerID; TargetObject = map; base.Invoke(parameter); } } } and you can use it in Layer template this way: Note that the action should also initialize the symbol depending on the geometry type of the layer, but this is not done in my sample.

JenniferNery · Answer

You can still use SpatialQueryAction but put it outside the Legend's Template. Name the button that this action belongs to so you may retrieve and set the Trigger for this element (in Post# 4, 2nd code snippet).

In your Legend Template, add a button or checkbox that will allow you to select sub layer of interest. In its click or checked event, set the SpatialQueryAction Url so that the next time it is performed it would be for the this sub layer  (in Post# 4, 1st + 2nd code snippets). Url and Symbol properties should be updated depending on the selected sub layer and its geometry type.

KirkKuykendall · Answer

Hi Jennifer -

Yes, I'm familiar with that sample.  The selection is hardwired for US States.

I'd like to allow the user to quickly choose which layer from within that mapservice he wants to select features from.

I'm already using the Legend.  I'd like to add a button next to each layer in the tree and bind the SpatialQueryAction to whatever layer the button is on.  This would allow the user to select things from that layer.  At the leaves of the legend tree I would also like to use the symbol item value in the where clause of the spatialqueryaction.

Thanks, Kirk