How can I copy all KmlNodes (and children nodes) from one KmlDocument to another KmlDocument

[justinfernandes]

IEnumerable<Layer> layers_to_export = this.ViewModel.Map.OperationalLayers.Where(I => I.Name.Equals(activeLayerName)).ToList();

            foreach (var layer_to_export in layers_to_export)
            {
                if (layer_to_export.Name.EndsWith("kmz") || layer_to_export.Name.EndsWith("KMZ"))
                {

                    var kml_layer = layer_to_export.Clone() as KmlLayer;
                    await kml_layer.LoadAsync();

                    KmlDocument kmlDoc = new KmlDocument();
     

                    KmlDataset kmlDataset = new KmlDataset(kmlDoc);




                    foreach (var node in kml_layer.Dataset.RootNodes)
                    {

                        kmlDoc.ChildNodes.Add(node);
                    }

                }
            }

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When this code is run, an exception is thrown at line 22: "kmlDoc.ChildNodes.Add(node);".  

Exception:  Esri.ArcGISRuntime.ArcGISRuntimeException: 'Object already owned.: Already owned.'

I have found that a similar exception is thrown (from some google searching) when attempting to add a reference of an object that is already being "used" somewhere else.  In this case i presume that the node being Add() to the ChildNodes of the kmlDoc is already owned by the kml_layer  object, therefore it cannot be added.

I am going down the path of recreating everything in the kml from scratch via parsing the kml manually. I feel like this could be done with much less code...but i havent been able to figure it out.

Thank you.

[DominiqueBroux · Accepted solution]

A KML node can't belong to multiple containers such as KML folders or KML documents.
Before adding a node to a new document you have to remove it from its initial document.

[TonyWakim · Accepted solution]

Justin,

Have you tried using KmlNode.SaveAsAsync()? 

 KmlNode.SaveAsAsync Method