C# Lucene获取所有索引

Question

我正在使用Lucene开发一个Windows应用程序。我想获取所有已索引的关键词，并将它们用作搜索字段自动建议的来源。如何在Lucene中收集所有已索引的关键词？我在C#方面还很新手，如果有代码示例就更好了。谢谢。

- user348348

Answer 1

您是否想从索引中提取所有术语？

private void GetIndexTerms(string indexFolder)
{
    List<String> termlist = new ArrayList<String>();
    IndexReader reader = IndexReader.open(indexFolder);
    TermEnum terms = reader.terms();
    while (terms.next()) 
    {
      Term term = terms.term();
      String termText = term.text();
      int frequency = reader.docFreq(term);
      termlist.add(termText);
    }
    reader.close();
}

- Mikos

Answer 2

如果需要关于Apache Lucene.Net版本4.8方面的灵感，你可以参考GitHubmsigut/LuceneNet48Demo。使用以下类： SearcherManager、*QueryParser和IndexWriter 来构建索引。

    // you favorite Query parser (MultiFieldQueryParser for example)
    _queryParser = new MultiFieldQueryParser(...

    // Execute the search with a fresh indexSearcher
    _searchManager.MaybeRefreshBlocking();

    var searcher = _searchManager.Acquire();
    try
    {
        var q = _queryParser.Parse(query);

        var topDocs = searcher.Search(q, 10);

        foreach (var scoreDoc in topDocs.ScoreDocs)
        {
            var document = searcher.Doc(scoreDoc.Doc);

            var hit = new QueryHit
            {
                Title = document.GetField("title")?.GetStringValue(),

                // ... you logic to read data from index ...
            };
        }
    }
    finally
    {
        _searchManager.Release(searcher);
        searcher = null;
    }

- Martin