重建Lucene索引的正确方法是什么

deletable 文件。我想这是因为每次我想重建索引时都会清空索引。下面是处理索引的代码:

public class SearchService : ISearchService
{
    Directory   IndexFileLocation;
    IndexWriter Writer;
    IndexReader Reader; 
    Analyzer    Analyzer;

    public SearchService(String indexLocation)
    {
        IndexFileLocation = FSDirectory.GetDirectory(indexLocation, System.IO.Directory.Exists(indexLocation) == false);
        Reader            = IndexReader.Open(IndexFileLocation);
        Writer            = new IndexWriter(IndexFileLocation, Analyzer, IndexFileLocation.List().Length == 0);
        Analyzer          = new StandardAnalyzer();
    }

    public void ClearIndex()
    {
        var DocumentCount = Writer.DocCount();
        if (DocumentCount == 0)
            return;

        for (int i = 0; i < DocumentCount; i++)
            Reader.DeleteDocument(i);
    }

    public void AddToSearchIndex(ISearchableData Data)
    {
        Document Doc = new Document();

        foreach (var Entry in Data)
        {
            Field field = new Field(Entry.Key, 
                                    Entry.Value, 
                                    Lucene.Net.Documents.Field.Store.NO, 
                                    Lucene.Net.Documents.Field.Index.TOKENIZED, 
                                    Lucene.Net.Documents.Field.TermVector.WITH_POSITIONS_OFFSETS);
            Doc.Add(field);
        }

        Field KeyField = new Field(
            SearchField.Key.ToString(), 
            Data.Key, 
            Lucene.Net.Documents.Field.Store.YES, 
            Lucene.Net.Documents.Field.Index.NO);

        Doc.Add(KeyField);
        Writer.AddDocument(Doc);
    }

    public void Dispose()
    {
        Writer.Optimize();
        Writer.Close();
        Reader.Close();
    }
}

下面是执行这一切的代码:

    private void btnRebuildIndex_Click(object sender, EventArgs e)
    {
        using (var SearchService = new SearchService(Application.StartupPath + @"\indexs\"))
        {
            SearchService.ClearIndex();
        }

        using (var SearchService = new SearchService(Application.StartupPath + @"\indexs\"))
        {
            Int32 BatchSize = 50;
            Int32 Current = 0;
            var TotalQuestions = SubmissionService.GetQuestionsCount();

            while (Current < TotalQuestions)
            {
                var Questions = SubmissionService.ListQuestions(Current, BatchSize, "Id", Qsparx.SortOrder.Asc);

                foreach (var Question in Questions)
                {
                    SearchService.AddToSearchIndex(Question.ToSearchableData());
                }

                Current += BatchSize;
            }
        }
    }