How to add individual layer of WMS group layer to ArcMap?

Question

I am attempting to add a single WMS layer that is part of a WMS service group layer. I am writing code to do this using ArcObjects in C# .Net. So far I have been unsuccessful. I can either only add the whole group layer, or I can add the individual WMS sub-layer but the full group is also still added.

Here is the code I have tried. I have allowed the user to select a layer from a list, and this code is trying to only add that selected layer.

 IWMSGroupLayer wmsMapLayer = new WMSMapLayerClass();
 IWMSConnectionName connName = new WMSConnectionNameClass();
 IPropertySet propSet = new PropertySetClass();
 propSet.SetProperty("URL", "http://www.___________________?");
 connName.ConnectionProperties = propSet;
 IDataLayer dataLayer = (IDataLayer)wmsMapLayer;
 dataLayer.Connect((IName)connName);
 IWMSServiceDescription serviceDesc = wmsMapLayer.WMSServiceDescription;
 IWMSLayerDescription groupDesc = serviceDesc.LayerDescription[0];
 for (int i = 0; i < groupDesc.LayerDescriptionCount - 1; i++)
 {
 IWMSLayerDescription layerDesc = groupDesc.LayerDescription[i];
 if (layerDesc.Title == lstWMSLayers.SelectedItem.ToString())//Checking if this is the selected layer
 {
 ILayer newLayer;
 IWMSLayer newWMSLayer = wmsMapLayer.CreateWMSLayer(layerDesc);
 newLayer = (ILayer)newWMSLayer;
 wmsMapLayer.InsertLayer(newLayer, 0);
 IMxDocument mxDoc = (IMxDocument)ArcMap.Application.Document;
 mxDoc.FocusMap.AddLayer((ILayer)wmsMapLayer);
 IActiveView activeView = (IActiveView)mxDoc.FocusMap;
 activeView.Refresh();
 }
 }

In ArcMap I get the following tree of layers

• WMS Service Group Layer
  • Selected WMS Layer
  • WMS Group Layer
    • All the layers that are part of the service...

Any suggestions?

• Petr Krebs: Are you able to add that layer (and that layer only) through the ArcMap user interface?
• JeremyFon: Yes, when I add an individual layer through ArcMap, I get the WMS Service Group Layer, and then only the one WMS layer, nothing else. So it should be possible through ArcObjects too right?

Answer 1

You need to clear the WMS Service Group Layer before adding the single WMSMapLayer.

wmsMapLayer.Clear();
wmsMapLayer.InsertLayer(newLayer, 0);

Note that this will remove all group/map layers from the WMS Service Group Layer, so if you're adding more than one, it might be advisable to not call wmsMapLayer.Clear() in the body of your loop. I haven't tested as I'm only adding a single layer, but perhaps instead, loop through groupDesc.LayerDescriptionCount and grab all the layerDesc objects that match your criteria, then Clear() and add the selected WMS layers back in.