/// <summary>
        /// 生成文章索引
        /// </summary>
        /// <param name="itemCallback"></param>
        public void MakeLuceneIndex(Action <Document> callback)
        {
            List <Article>  list         = dao.GetArticleList();
            List <Document> documentList = new List <Document>();

            foreach (Article item in list)
            {
                Document indexDoc = new Document();

                #region 根据需要添加要被索引的数据列

                indexDoc.Add(new Field("Id", string.Concat("", item.Id), Field.Store.YES, Field.Index.ANALYZED));
                indexDoc.Add(new Field("Title", item.Title, Field.Store.YES, Field.Index.ANALYZED));
                indexDoc.Add(new Field("Content", item.Content, Field.Store.YES, Field.Index.ANALYZED));

                #endregion 根据需要添加要被索引的数据列

                documentList.Add(indexDoc);
                LuceneManager.MakeIndex(documentList, directoryPath, callback);
            }
        }