Copy Taxonomy Column from one listitem to another listitem

Question

I am trying to copy a Listitem having Taxonomy column with multi values from one list to another list in a sharepoint online. In the both lists Taxonomy metadata column are created. I am able to get the TaxonomyFieldValueCollection values but some how i am not able to set the values in the destination lists. I have gone through the stackeoverflow post link, but unable to set the Taxonomy values in the Destination list. Below is my code.Iam getting no error

    using (var sourceContext = new ClientContext(SourceSiteCollectionurl))
            {
                sourceContext.Credentials = new SharePointOnlineCredentials(UserName, secure);
                List SourceList = sourceContext.Web.Lists.GetByTitle(listName);
                Microsoft.SharePoint.Client.ListItem item = SourceList.GetItemById(1);
                sourceContext.Load(item);
                sourceContext.ExecuteQuery();
                TaxonomyFieldValueCollection sourceValue = item["Related_x0020_Party"] as TaxonomyFieldValueCollection;
                string ss = "";  
                 List<string> termValues = new List<string>();
                foreach (TaxonomyFieldValue taxProductFieldValue in sourceValue)
                {
                    // sb_ProductFieldValue.Append(taxProductFieldValue.TermGuid + "|");
                     termValues.Add(taxProductFieldValue.WssId + ";#" + taxProductFieldValue.Label + "|" + taxProductFieldValue.TermGuid);
                  //  ss += taxProductFieldValue.Label + "|" + taxProductFieldValue.TermGuid + ";";
                }
               List targetList = sourceContext.Web.Lists.GetByTitle("Project Department");
                Microsoft.SharePoint.Client.ListItem targetItem = targetList.GetItemById(2);
                sourceContext.Load(targetList.Fields);
                sourceContext.Load(targetItem);
                sourceContext.ExecuteQuery();
                targetItem["Related_x0020_Party"] = termValues;
                targetItem.Update();
                sourceContext.Load(targetItem);
                sourceContext.ExecuteQuery();
    }

Any help Please..

Update: I tried to set the values using List termValues = new List(); but the filed is not updating. No error no output

Answer 1

Finally the below code works fine for me. Creating a list of string type and joining the array items with ";"

        using (var sourceContext = new ClientContext(SourceSiteCollectionurl))
            {
                sourceContext.Credentials = new SharePointOnlineCredentials(UserName, secure);
                List SourceList = sourceContext.Web.Lists.GetByTitle(listName);
                Microsoft.SharePoint.Client.ListItem item = SourceList.GetItemById(1);
                sourceContext.Load(item);
                sourceContext.ExecuteQuery();
                TaxonomyFieldValueCollection sourceValue = item["Related_x0020_Party"] as TaxonomyFieldValueCollection;
                string[] termValuesarrary;
                List<string> termValues = new List<string>();
                foreach (TaxonomyFieldValue taxProductFieldValue in sourceValue)
                {
                    termValues.Add(taxProductFieldValue.Label + "|" + taxProductFieldValue.TermGuid);
                }
                termValuesarrary = termValues.ToArray();
                string strtermValues = string.Join(";", termValuesarrary);
                List targetList = sourceContext.Web.Lists.GetByTitle("Project Department");
                Microsoft.SharePoint.Client.ListItem targetItem = targetList.GetItemById(2);
                sourceContext.Load(targetList.Fields);
                sourceContext.Load(targetItem);
                sourceContext.ExecuteQuery();
                targetItem["Related_x0020_Party"] = strtermValues;
                targetItem.Update();
                sourceContext.Load(targetItem);
                sourceContext.ExecuteQuery();
            }

Answer 2

Did you try the following:

targetItem["Related_x0020_Party"] = sourceValue;
targetItem.Update();
sourceContext.Load(targetItem);
sourceContext.ExecuteQuery();