ArcGIS Pro二次开发-获得字段唯一值

        private List<string> getunValue(FeatureLayer aFeatureLayer, string FieldName)
        {

            QueryFilter qf = new QueryFilter()
            {
                PrefixClause = "DISTINCT",              //DISTINCT does not work in this query. See workaround below.
                SubFields = FieldName,
                WhereClause = FieldName + " IS NOT NULL",
                PostfixClause = "ORDER BY " + FieldName
            };

            List<string> pList = new List<string>();


            QueuedTask.Run(() =>
            {
                RowCursor rows = aFeatureLayer.Search(qf);
                int fldIndex = rows.FindField(FieldName);

              
                while (rows.MoveNext())
                {
                    string value = rows.Current.GetOriginalValue(fldIndex) as string;
                    pList.Add(value);
                }
                MessageBox.Show("" + pList.Count);
                return pList;
            });
            return null;
        }