ARCGis LayerToKML Skips Feature Layers and Doesn't Process Layers in Group Layers

Question

I am using ARCGis desktop and have written a quick conversion program to convert my layers to kml but I ran into some issues. It seems the only layers it can process correctly are group layers.

When it processes the group layers I am missing all the feature layers included in the group layer in the resulting doc.kml. It's also failing on feature layers with an error that says it's not a layer with the following message: ERROR 000840: The value is not a Layer. When I know it's a layer, I can pull it up in ARCMap and, indeed, ARCMap agrees with me that it's a layer. I can use the MapToKML function without issue but I need to control my layers individually so I was hoping I can generate KML for each individual layer on a map.

Thanks in advance for any help you can provide.

Here is my source code:

  static void Main(string[] args)
  {
   IMapDocument mapDocument = new MapDocumentClass();
   IPage page;

   string mapFilename = @"c:\maps\BaseMap_NAD83_SD_StatePlane_Plumes_Scott.mxd";

   Console.WriteLine("Initializing GEO...");
   Geoprocessor GP = new Geoprocessor();

   if (mapDocument.get_IsMapDocument(mapFilename) && mapDocument.get_IsPresent(mapFilename))
   {
    Console.WriteLine("Loading map...");
    mapDocument.Open(mapFilename, "");

    page = mapDocument.PageLayout.Page;

    IMap map;
    for (int iMapIndex = 0; iMapIndex < mapDocument.MapCount; iMapIndex++)
    {
     map = mapDocument.get_Map(iMapIndex);

     Console.WriteLine("Converting layers for map {0}...", map.Name);

     ILayer layer;
     for (int iLayerIndex = 0; iLayerIndex < map.LayerCount; iLayerIndex++)
     {
      layer = map.get_Layer(iLayerIndex);


      ConvertLayerToKML(GP, layer as ILayer2);

      Marshal.ReleaseComObject(layer);
     }

     Marshal.ReleaseComObject(map);
    }
   }

   mapDocument.Close();
   Marshal.ReleaseComObject(mapDocument);
  }

  private static string[] ConvertLayerToKML(Geoprocessor GP, ILayer2 layer)
  {
   string [] messages = new string[] {};

   string layerName = layer.Name;

   LayerToKML layerToKML = new LayerToKML();
   layerToKML.layer = layer;
   layerToKML.layer_output_scale = 10000;
   layerToKML.out_kmz_file = string.Format("{0}.kmz", layerName);

   Console.WriteLine("Converting layer {0}", layerName);

   object result = GP.Execute(layerToKML, null);

   messages = new string[GP.MessageCount];
   for (int i = 0; i < GP.MessageCount; i++)
   {
    messages[i] = GP.GetMessage(i);
   }

   return messages;
  }

Answer 1

I it doesn't work with group layers, try to cast the layer to an ICompositeLayer and loop through the individual layers.