(一)简单搜索

1界面

1.1抓图：

原则:  简化，直观，说明问题，有用

1.2说明：

1 对指定文件夹创建索引

2 输入关键词，显示查询结果

2 实现

2.1 创建

button1_Click方法：

//对制定文件夹建立索引
        private void button1_Click(object sender, EventArgs e1)
        {

            System.IO.FileInfo docDir = new System.IO.FileInfo(textBox1.Text);
            System.DateTime start = System.DateTime.Now;
            try
            {
                //索引生成器IndexWriter，  标准分析器StandardAnalyzer
                IndexWriter writer = new IndexWriter(FSDirectory.Open(INDEX_DIR),
                    new StandardAnalyzer(Version.LUCENE_CURRENT), true, IndexWriter.MaxFieldLength.LIMITED);
                IndexDocs(writer, docDir);
                writer.Optimize();
                writer.Close();

                System.DateTime end = System.DateTime.Now;
                int TotalMilliSeconds = end.Millisecond - start.Millisecond;
                MessageBox.Show("索引完成！total  " + TotalMilliSeconds + "  milliseconds");
            }
            catch (System.IO.IOException e)
            {
                MessageBox.Show(" caught a " + e.GetType() + "\n with message: " + e.Message);
            }  

        }

IndexDocs方法：

//遍历目录，对每个文档建立索引
        internal static void IndexDocs(IndexWriter writer, System.IO.FileInfo file)
        {
            // do not try to index files that cannot be read
            // if (file.canRead())  // {{Aroush}} what is canRead() in C#?
            {
                if (System.IO.Directory.Exists(file.FullName))  //目录递归
                {
                    System.String[] files = System.IO.Directory.GetFileSystemEntries(file.FullName);
                    // an IO error could occur
                    if (files != null)
                    {
                        for (int i = 0; i < files.Length; i++)
                        {
                            IndexDocs(writer, new System.IO.FileInfo(files[i]));
                        }
                    }
                }
                else   //对文件建立索引
                {
                    System.Console.Out.WriteLine("adding " + file);
                    try
                    {
                        writer.AddDocument(FileDocument.Document(file));     //#####key
                    }
                    // at least on windows, some temporary files raise this exception with an "access denied" message
                    // checking if the file can be read doesn‘t help
                    catch (System.IO.FileNotFoundException fnfe)
                    {
                        ;
                    }
                }
            }
        }

2.2 查询

button2_Click方法

 //查询
        private void button2_Click(object sender, EventArgs e)
        {
            dataGridView1.Rows.Clear();
            System.String KeyWord = textBox2.Text;

            System.String index = "index";
            System.String field = "contents";
            System.String normsField = null;

            //1 初始化reader， searcher
            IndexReader reader = IndexReader.Open(FSDirectory.Open(new System.IO.FileInfo(index)), true); // only searching, so read-only=true
            if (normsField != null) //规范标准
                reader = new OneNormsReader(reader, normsField);
            Searcher searcher = new IndexSearcher(reader);      //搜索器
            Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_CURRENT);
            QueryParser parser = new QueryParser(field, analyzer);      //关键字解析器：指定类型field，分词方法analyzer

            //2 解析关键字
            if (KeyWord == null || KeyWord.Length == -1)
                return;
            KeyWord = KeyWord.Trim();
            if (KeyWord.Length == 0)
                return;
            Query query = parser.Parse(KeyWord);
            System.Console.Out.WriteLine("Searching for: " + query.ToString(field));

            //3 获取查询结果hits
            Hits hits = searcher.Search(query);     //Hits
            for (int i = 0; i < hits.Length(); i++)
            {
                Document doc = hits.Doc(i);
                string fullName = doc.Get("path");      //####key
                string name = fullName.Substring(fullName.LastIndexOf("\\") + 1,
                    fullName.Length - 1 - fullName.LastIndexOf("\\"));

                DataGridViewRow dr = new DataGridViewRow();
                int index1 = dataGridView1.Rows.Add(dr);
                dataGridView1.Rows[index1].Cells[0].Value = name;
                dataGridView1.Rows[index1].Cells[1].Value = fullName;
            }

            searcher.Close();
            reader.Close();
        }

3总结

3.1方法：

1 逐层推进： 逻辑 -- 层次1  -- 层次2

2 抓住核心： //####key

3 源代码注释分段，预想猜测

3.2知识点：

1  生成索引： indexWriter.AddDocument(FileDocument.Document(file));

2  解析关键字： Query query = parser.Parse(KeyWord);

3  获取查询结果： Hits hits = searcher.Search(query);

3.3心态：

自然流畅，不追求完美。

循环练习，逐渐接近，形成模板。

Vs移除项目不会导致删除

4 下一步

文档摘要

中文支持