如何在Lucene.net中突出顯示搜索到的關鍵字？

Question

我創建了一個Lucene.net項目。我想突出顯示搜索的關鍵字。

如何使用Lucene.net搜索來突出顯示這些關鍵字？

Answer 1

#region search hightligh 
     public static IEnumerable<Models.Post> SearchHighligh(string input, string fieldName = "") 
     { 
      if (string.IsNullOrEmpty(input)) return new List<Models.Post>(); 

      var terms = input.Trim().Replace("-", " ").Split(' ') 
       .Where(x => !string.IsNullOrEmpty(x)).Select(x => x.Trim() + "*"); 
      input = string.Join(" ", terms); 

      return _searchHighligh(input, fieldName); 
     } 
     private static string getHighlight(Highlighter highlighter, StandardAnalyzer analyzer, string fieldContent) 
     { 
      Lucene.Net.Analysis.TokenStream stream = analyzer.TokenStream("", new StringReader(fieldContent)); 
      return highlighter.GetBestFragments(stream, fieldContent, 1, "."); 
     } 


     private static IEnumerable<Models.Post> _searchHighligh(string searchQuery, string searchField = "") 
     { 
      // validation 
      if (string.IsNullOrEmpty(searchQuery.Replace("*", "").Replace("?", ""))) return new List<Models.Post>(); 

      // set up lucene searcher 
      using (var searcher = new IndexSearcher(_directory, false)) 
      { 
       var hits_limit = 1000; 
       var analyzer = new StandardAnalyzer(Lucene.Net.Util.Version.LUCENE_30); 

       IFormatter formatter = new SimpleHTMLFormatter("<span style=\"font-weight:bold; background-color:yellow;\">", "</span>"); 
       SimpleFragmenter fragmenter = new SimpleFragmenter(1000); 
       QueryScorer scorer = null; 

       ScoreDoc[] hits; 
       // search by single field 
       if (!string.IsNullOrEmpty(searchField)) 
       { 
        var parser = new QueryParser(Lucene.Net.Util.Version.LUCENE_30, searchField, analyzer); 
        var query = parseQuery(searchQuery, parser); 
        scorer = new QueryScorer(query); 
        hits = searcher.Search(query, hits_limit).ScoreDocs; 

       } 
       // search by multiple fields (ordered by RELEVANCE) 
       else 
       { 
        var parser = new MultiFieldQueryParser 
         (Lucene.Net.Util.Version.LUCENE_30, new[] { "Title", "Body" }, analyzer); 
        var query = parseQuery(searchQuery, parser); 
        scorer = new QueryScorer(query); 
        hits = searcher.Search(query, null, hits_limit, Sort.INDEXORDER).ScoreDocs; 

       } 
       Highlighter highlighter = new Highlighter(formatter, scorer); 
       highlighter.TextFragmenter = fragmenter; 
       var results = _mapLuceneToDataListHighligh(hits, searcher, highlighter, analyzer); 
       analyzer.Close(); 
       searcher.Dispose(); 
       return results; 
      } 
     } 
     private static IEnumerable<Models.Post> _mapLuceneToDataListHighligh(IEnumerable<ScoreDoc> hits, IndexSearcher searcher, Highlighter highlighter, StandardAnalyzer analyzer) 
     { 
      // v 2.9.4: use 'hit.doc' 
      // v 3.0.3: use 'hit.Doc' 
      return hits.Select(hit => _mapLuceneDocumentToDataHighligh(searcher.Doc(hit.Doc), highlighter, analyzer)).ToList(); 
     } 
     private static Models.Post _mapLuceneDocumentToDataHighligh(Document doc, Highlighter highlighter, StandardAnalyzer analyzer) 
     { 
      return new Models.Post 
      { 
       Id = Convert.ToInt32(doc.Get("Id")), 
       //Title = getHighlight(highlighter, analyzer,doc.Get("Title")), 
       Title =doc.Get("Title"), 
       Body = getHighlight(highlighter, analyzer, doc.Get("Body")), 
       SiteId = Convert.ToInt16(doc.Get("SiteId")), 
       PostTypeId = Convert.ToInt32(doc.Get("PostTypeId")), 
       OwnerUserId = Convert.ToInt32(doc.Get("OwnerUserId")), 
       ParentId = Convert.ToInt32(doc.Get("ParentId")), 
       CreationDate = UTILS.Function.getDateTime((doc.Get("CreationDate")), "g") 
      }; 
     } 
     #endregion