利用Boost影响Lucene查询结果的排序

private void btnSearch_Click(object sender, EventArgs e)

        {

            RAMDirectory ramDir = new RAMDirectory();

            IndexWriter iw = new IndexWriter(ramDir,new StandardAnalyzer(),true);



            string[] NameList = { "you are my friend", "you are my wife", "I love you" };

            string[] FileList = { "1", "2", "3" };



            for (int i = 0; i < NameList.Length; i++)

            {

                Document doc = new Document();

                doc.Add(new Field("name", NameList[i], Field.Store.YES, Field.Index.TOKENIZED));

                doc.Add(new Field("file", FileList[i], Field.Store.YES, Field.Index.TOKENIZED));



                if (i == 2) { doc.SetBoost(2.0f); }//这里设置了第三个文档优先级最高，所以在搜索出来的结果中，该文档排在最前

                iw.AddDocument(doc);

            }

            iw.Close();



            IndexSearcher _searcher = new IndexSearcher(ramDir);

            QueryParser _parser = new QueryParser("name",new StandardAnalyzer());

            Query  _query = _parser.Parse("you");

            Hits hitDoc = _searcher.Search(_query);



            lstResult.Items.Clear();//lstResult为一个ListBox



            for (int i = 0; i < hitDoc.Length(); i++)

            {

                Document doc = hitDoc.Doc(i);

                lstResult.Items.Add(doc.Get("file") + " " + doc.Get("name"));

            }            

            _searcher.Close();

        }