public void Execute(ESRI.ArcGIS.esriSystem.IArray paramvalues, ESRI.ArcGIS.esriSystem.ITrackCancel TrackCancel, ESRI.ArcGIS.Geoprocessing.IGPEnvironmentManager envMgr, ESRI.ArcGIS.Geodatabase.IGPMessages message)
        {
            try
            {
                IGPUtilities3 gpUtilities3 = new GPUtilitiesClass();

                if (TrackCancel == null)
                {
                    TrackCancel = new CancelTrackerClass();
                }

                IGPValue inputLayersGPValue = gpUtilities3.UnpackGPValue(paramvalues.get_Element(in_LayersNumber));
                IGPMultiValue inputLayersMultiValue = gpUtilities3.UnpackGPValue(inputLayersGPValue) as IGPMultiValue;

                IGPParameter outputGroupLayerParameter = paramvalues.get_Element(out_groupLayerNumber) as IGPParameter;
                IGPValue outputGPGroupLayer = gpUtilities3.UnpackGPValue(outputGroupLayerParameter);
                IGPCompositeLayer outputCompositeLayer = outputGPGroupLayer as IGPCompositeLayer;

                if (outputCompositeLayer == null)
                {
                    message.AddError(120048, string.Format(resourceManager.GetString("GPTools_NullPointerParameterType"), outputGroupLayerParameter.Name));
                    return;
                }

                IGroupLayer groupLayer = null;

                // find the last position of the "\" string
                // in case we find such a thing, i.e. position is >= -1 then let's assume that we are dealing with a layer file on disk
                // otherwise let's create a new group layer instance
                string outputGPLayerNameAsString = outputGPGroupLayer.GetAsText();
                int separatorPosition = outputGPLayerNameAsString.LastIndexOf(System.IO.Path.DirectorySeparatorChar);
                string layerName = String.Empty;

                if (separatorPosition > -1)
                {
                    layerName = outputGPGroupLayer.GetAsText().Substring(separatorPosition + 1);
                }
                else
                {
                    layerName = outputGPGroupLayer.GetAsText();
                }

                ILayer foundLayer = null;
                IGPLayer existingGPLayer = gpUtilities3.FindMapLayer2(layerName, out foundLayer);

                if (foundLayer != null)
                {
                    gpUtilities3.RemoveFromMapEx((IGPValue)existingGPLayer);
                    gpUtilities3.RemoveInternalLayerEx(foundLayer);
                }

                groupLayer = new GroupLayer();
                ((ILayer)groupLayer).Name = layerName;

                for (int layerIndex = 0; layerIndex < inputLayersMultiValue.Count; layerIndex++)
                {
                    IGPValue gpLayerToAdd = inputLayersMultiValue.get_Value(layerIndex) as IGPValue;

                    ILayer sourceLayer = gpUtilities3.DecodeLayer(gpLayerToAdd);

                    groupLayer.Add(sourceLayer);
                }

                outputGPGroupLayer = gpUtilities3.MakeGPValueFromObject(groupLayer);

                if (separatorPosition > -1)
                {
                    try
                    {
                        // in the case that we are dealing with a layer file on disk
                        // let's persist the group layer information into the file
                        ILayerFile pointLayerFile = new LayerFileClass();

                        if (System.IO.Path.GetExtension(outputGPLayerNameAsString).ToUpper().Equals(".LYR"))
                        {
                            if (pointLayerFile.get_IsPresent(outputGPLayerNameAsString))
                            {
                                try
                                {
                                    gpUtilities3.Delete(outputGPGroupLayer);
                                }
                                catch (Exception ex)
                                {
                                    message.AddError(120001, ex.Message);
                                    return;
                                }
                            }

                            pointLayerFile.New(outputGPLayerNameAsString);

                            pointLayerFile.ReplaceContents(groupLayer);

                            pointLayerFile.Save();

                        }

                         outputGPGroupLayer = gpUtilities3.MakeGPValueFromObject(pointLayerFile.Layer);
                    }
                    catch (Exception ex)
                    {
                        message.AddError(120002, ex.Message);
                        return;
                    }
                }

                gpUtilities3.PackGPValue(outputGPGroupLayer, outputGroupLayerParameter);

            }
            catch (Exception ex)
            {
                message.AddError(120049, ex.Message);
            }
        }
        public void Execute(ESRI.ArcGIS.esriSystem.IArray paramvalues, ESRI.ArcGIS.esriSystem.ITrackCancel TrackCancel, ESRI.ArcGIS.Geoprocessing.IGPEnvironmentManager envMgr, ESRI.ArcGIS.Geodatabase.IGPMessages message)
        {
            try
            {
                IGPUtilities3 gpUtilities3 = new GPUtilitiesClass();

                if (TrackCancel == null)
                {
                    TrackCancel = new CancelTrackerClass();
                }

                IGPValue      inputLayersGPValue    = gpUtilities3.UnpackGPValue(paramvalues.get_Element(in_LayersNumber));
                IGPMultiValue inputLayersMultiValue = gpUtilities3.UnpackGPValue(inputLayersGPValue) as IGPMultiValue;

                IGPParameter      outputGroupLayerParameter = paramvalues.get_Element(out_groupLayerNumber) as IGPParameter;
                IGPValue          outputGPGroupLayer        = gpUtilities3.UnpackGPValue(outputGroupLayerParameter);
                IGPCompositeLayer outputCompositeLayer      = outputGPGroupLayer as IGPCompositeLayer;

                if (outputCompositeLayer == null)
                {
                    message.AddError(120048, string.Format(resourceManager.GetString("GPTools_NullPointerParameterType"), outputGroupLayerParameter.Name));
                    return;
                }


                IGroupLayer groupLayer = null;

                // find the last position of the "\" string
                // in case we find such a thing, i.e. position is >= -1 then let's assume that we are dealing with a layer file on disk
                // otherwise let's create a new group layer instance
                string outputGPLayerNameAsString = outputGPGroupLayer.GetAsText();
                int    separatorPosition         = outputGPLayerNameAsString.LastIndexOf(System.IO.Path.DirectorySeparatorChar);
                string layerName = String.Empty;

                if (separatorPosition > -1)
                {
                    layerName = outputGPGroupLayer.GetAsText().Substring(separatorPosition + 1);
                }
                else
                {
                    layerName = outputGPGroupLayer.GetAsText();
                }

                ILayer   foundLayer      = null;
                IGPLayer existingGPLayer = gpUtilities3.FindMapLayer2(layerName, out foundLayer);

                if (foundLayer != null)
                {
                    gpUtilities3.RemoveFromMapEx((IGPValue)existingGPLayer);
                    gpUtilities3.RemoveInternalLayerEx(foundLayer);
                }

                groupLayer = new GroupLayer();
                ((ILayer)groupLayer).Name = layerName;

                for (int layerIndex = 0; layerIndex < inputLayersMultiValue.Count; layerIndex++)
                {
                    IGPValue gpLayerToAdd = inputLayersMultiValue.get_Value(layerIndex) as IGPValue;

                    ILayer sourceLayer = gpUtilities3.DecodeLayer(gpLayerToAdd);

                    groupLayer.Add(sourceLayer);
                }

                outputGPGroupLayer = gpUtilities3.MakeGPValueFromObject(groupLayer);

                if (separatorPosition > -1)
                {
                    try
                    {
                        // in the case that we are dealing with a layer file on disk
                        // let's persist the group layer information into the file
                        ILayerFile pointLayerFile = new LayerFileClass();

                        if (System.IO.Path.GetExtension(outputGPLayerNameAsString).ToUpper().Equals(".LYR"))
                        {
                            if (pointLayerFile.get_IsPresent(outputGPLayerNameAsString))
                            {
                                try
                                {
                                    gpUtilities3.Delete(outputGPGroupLayer);
                                }
                                catch (Exception ex)
                                {
                                    message.AddError(120001, ex.Message);
                                    return;
                                }
                            }

                            pointLayerFile.New(outputGPLayerNameAsString);

                            pointLayerFile.ReplaceContents(groupLayer);

                            pointLayerFile.Save();
                        }

                        outputGPGroupLayer = gpUtilities3.MakeGPValueFromObject(pointLayerFile.Layer);
                    }
                    catch (Exception ex)
                    {
                        message.AddError(120002, ex.Message);
                        return;
                    }
                }

                gpUtilities3.PackGPValue(outputGPGroupLayer, outputGroupLayerParameter);
            }
            catch (Exception ex)
            {
                message.AddError(120049, ex.Message);
            }
        }