• 利用Lucene.net实现检索并对检索关键字高亮显示


    Lucene.NET是一个全文搜索框架,而不是应用产品。

    关于其中用到的两个dll文件,可到http://d.download.csdn.net/down/2352061/taomanman免费下载。

     直接贴代码了:

    <%@ Page Language="C#" AutoEventWireup="true" CodeFile="xxjs.aspx.cs" Inherits="XXJS_xxjs" %>

    <%@ Register assembly="AspNetPager" namespace="Wuqi.Webdiyer" tagprefix="webdiyer" %>

    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

    <html xmlns="http://www.w3.org/1999/xhtml">
    <head runat="server">
        <title></title>
    </head>
    <body>
        <form id="form1" runat="server">
        <div>
            <div style="height:40px">
                <asp:Button ID="btnCreateIndex" Text="建立索引" runat="server" onclick="btnCreateIndex_Click" />
                <asp:Label ID="lbStatus" runat="server"></asp:Label>
            </div>
            <table>
                <tr>
                    <td><asp:TextBox ID="tbSearchContent" runat="server" Height="20px" Width="155px"></asp:TextBox></td>
                    <td><asp:Button ID="btnSearch" runat="server" Text="搜索" onclick="btnSearch_Click"/></td>
                </tr>
            </table>
            <div id="msg" runat="server" bordercolorlight="#99cc99" 
                bordercolordark="#669933" bgcolor="#dde3ce" style="background-color: #C0C0C0"></div>
                <div>
        <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" 
                        Width="100%" GridLines="None" AllowPaging="true" 
                        onpageindexchanging="GridView1_PageIndexChanging">
            <Columns>
                <asp:TemplateField>
                    <ItemTemplate>
                        <table width="100%" border="0" align="center" cellpadding="5" cellspacing="1">
                      <tr>
                       <td bgcolor="#ffffff" >
                        <font size="2"><asp:HyperLink ID="HyperLink1" runat="server" Text='<%#Eval("标题") %>' NavigateUrl='<%#Eval("链接地址") %>'></asp:HyperLink></font>
                       </td>
                      </tr>
                      <tr>
                          <td>
                              <font size="2"><%# this.getSubString(Eval("内容").ToString())%></font>
                          </td>
                      </tr>
                     </table>
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>
                </div>
              </div>
            </form>
        </body>
    </html>
    ----------------------------------------------------------------------------------------------------------------------------------------------------

    using System;
    using System.Configuration;
    using System.Data;
    using System.Linq;
    using System.Web;
    using System.Web.Security;
    using System.Web.UI;
    using System.Web.UI.HtmlControls;
    using System.Web.UI.WebControls;
    using System.Web.UI.WebControls.WebParts;
    using System.Xml.Linq;
    using System.Data.SqlClient;
    using System.Text;
    using System.IO;
    using System.Collections;
    using USTC;

    using Lucene.Net.Documents;
    using Lucene.Net.Index;
    using Lucene.Net.Search;
    using Lucene.Net.QueryParsers;
    using Lucene.Net.Analysis.Standard;
    using Lucene.Net.Store;
    using Lucene.Net.Highlight;
    using Lucene.Net.Analysis;

    public partial class XXJS_xxjs : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!Page.IsPostBack)
            {
                //只在画面第一次读取的时候取得资料
                VSDataTable = new DataTable();
            }
            PageDataBind(); //绑定资料
        }

        protected void btnCreateIndex_Click(object sender, EventArgs e)
        {
            CreateIndex();
        }

        //建立索引
        public IndexWriter CreateIndex()
        {
            string INDEX_STORE_PATH = Server.MapPath("index");  //INDEX_STORE_PATH 为索引存储目录
            //IndexReader reader = IndexReader.Open(INDEX_STORE_PATH);
            //Term term = new Term(field, key);
            //reader.DeleteDocuments(term);
            //reader.Close();
            IndexWriter writer = null;
            try
            {
                writer = new IndexWriter(INDEX_STORE_PATH, new StandardAnalyzer(), true);
                DM dm = new DM();
                string strSQL = "select c_title,c_text,c_url from v_searches";
                DataSet ds = dm.getsql(strSQL);
                //建立索引字段
                foreach (DataRowView drv in ds.Tables[0].DefaultView)
                {
                    Document doc = new Document();
                    doc.Add(new Field("标题", drv["c_title"].ToString(), Field.Store.YES, Field.Index.UN_TOKENIZED));
                    doc.Add(new Field("内容", drv["c_text"].ToString(), Field.Store.YES, Field.Index.UN_TOKENIZED));
                    doc.Add(new Field("链接地址", drv["c_url"].ToString(), Field.Store.YES, Field.Index.UN_TOKENIZED));
                    doc.Add(new Field("标题及内容", drv["c_title"].ToString() + drv["c_text"].ToString(), Field.Store.YES, Field.Index.TOKENIZED));//不存储,索引,标题及内容实现了标题和内容的索引
                    writer.AddDocument(doc);
                }
                writer.Optimize();
                writer.Close();

                this.lbStatus.Text = "索引建立成功!";
            }
            catch
            {
                this.lbStatus.Text = "索引已经创建过,无需重新创建!";
            }
            return writer;
        }

        //信息检索
        protected void btnSearch_Click(object sender, EventArgs e)
        {
            BindLuceneData();
        }

        public void BindLuceneData()
        {
            string INDEX_STORE_PATH = Server.MapPath("index");//INDEX_STORE_PATH 为索引存储目录 
            string keyword = tbSearchContent.Text;  //搜索关键字
            if (keyword != "")
            {
                Hits myhit = null;
                IndexSearcher mysea = new IndexSearcher(INDEX_STORE_PATH);
                Analyzer analyzer = new StandardAnalyzer();    //定义分词器 
                QueryParser q = new QueryParser("标题及内容", analyzer);
                Query query1 = q.Parse(keyword);

                //高亮显示
                BooleanQuery bquery = new BooleanQuery();
                Highlighter highlighter = new Highlighter(new SimpleHTMLFormatter("<font color=/"red/">", "</font>"), new QueryScorer(query1));//使用高亮关键字显示替代关键字
                highlighter.SetTextFragmenter(new SimpleFragmenter(100));

                DateTime start = DateTime.Now;
                myhit = mysea.Search(query1);
                DateTime end = DateTime.Now;
                long time = end.Millisecond - start.Millisecond;
                this.msg.InnerHtml = "<font size=2 >关于 <b><font color=blue>" + keyword + "</font><b/> 共搜索到<b><font color=red>" + myhit.Length() + "</font></b>个相关结果.搜索耗时:<font color=red>" + time + "</font>毫秒.</font></br>";

                if (myhit != null)
                {
                    DataRow myrow;
                    DataTable mytab = new DataTable();
                    mytab.Columns.Add("标题");
                    mytab.Columns.Add("内容");
                    mytab.Columns.Add("链接地址");
                    mytab.Clear();
                    for (int i = 0; i < myhit.Length(); i++)
                    {
                        Document doc = myhit.Doc(i);
                        myrow = mytab.NewRow();
                        myrow[0] = doc.Get("标题").ToString();
                        myrow[1] = doc.Get("内容").ToString();
                        myrow[2] = doc.Get("链接地址").ToString();

                        Lucene.Net.Analysis.TokenStream titleStream = analyzer.TokenStream("标题", new System.IO.StringReader(doc.Get("标题").ToString()));
                        string titleResult = highlighter.GetBestFragments(titleStream, doc.Get("标题").ToString(), 0, "...");
                        Lucene.Net.Analysis.TokenStream contentStream = analyzer.TokenStream("内容", new System.IO.StringReader(doc.Get("内容").ToString()));
                        string contentResult = highlighter.GetBestFragments(contentStream, doc.Get("内容").ToString(), 0, "...");
                        if (!string.IsNullOrEmpty(titleResult))
                        {
                            myrow[0] = titleResult;
                        }
                        if (!string.IsNullOrEmpty(contentResult))
                        {
                            myrow[1] = contentResult;
                        }
                        mytab.Rows.Add(myrow);
                        myrow.AcceptChanges();
                    }

                    GridView1.DataSource = mytab;
                    GridView1.DataBind();
                    ViewState["MyDataTable"] = mytab;
                }
                else
                {
                    Response.Write("Hits为空");
                }
                mysea.Close();
            }
            else
            {
                return;
            }
        }
            
        //分页事件
        protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
        {
            GridView1.DataSource = VSDataTable;
            GridView1.PageIndex = e.NewPageIndex;
            GridView1.DataBind();
        }
        
        /// <summary>
        /// 存放在ViewState的DataTable
        /// </summary>
        private DataTable VSDataTable
        {
            get { return ViewState["MyDataTable"] as DataTable; }
            set { ViewState["MyDataTable"] = value; }
        }

        /// <summary>
        /// 普通的绑定资料
        /// </summary>
        private void PageDataBind()
        {
            GridView1.DataSource = VSDataTable;
            GridView1.DataBind();
        }

        /// <summary>
        /// 绑定资料加换页
        /// </summary>
        /// <param name="getPageIndex">新页面Index</param>
        private void PageDataBind(Int32 getPageIndex)
        {
            GridView1.DataSource = VSDataTable;
            GridView1.PageIndex = getPageIndex;
            GridView1.DataBind();
        }

        public string getSubString(string str)
        {
            if (str.Length > 200)
                str = str.Substring(0, 197)+"  ...";
           return str;
        }

    }

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  • 原文地址:https://www.cnblogs.com/superfeeling/p/2552687.html
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