初战luncene.net(1)

   首先从http://incubator.apache.org/projects/lucene.net.html下载luncene.net的版本,由于它的原型是一个JAVA开源项目所以详细的资料可以查看luncene in action这本书,把压缩包解压会得到三个文件包 demo luncene.net  test,首先要先把luncene.net用vs生成一下,这样在bin目录就得到了luncene.net.dll了.
        luncene可以帮助我们搜索硬盘上的文件 还有 电子邮件,web页,当然也可以是数据库中的数据.
        第一步,是为我们所要搜索的对象建立索引.然后再对我们建立的索引进行搜索.
        建立索引,这里新建一个项目textIndexer,只针对.txt文件进行索引.首先luncene.net.dll在我们建立的项目里面把他添加引用.代码如下:在bin/debug目录下新建两个文件目录build/index  和luncene,其中luncene里面放如被索引的文件

using System;
using StandardAnalyzer = Lucene.Net.Analysis.Standard.StandardAnalyzer;
using Document = Lucene.Net.Documents.Document;
using IndexReader = Lucene.Net.Index.IndexReader;
using IndexWriter = Lucene.Net.Index.IndexWriter;
using Field = Lucene.Net.Documents.Field;
using System.IO;

namespace TextIndexer
{
    class textIndexer
    {
        static void Main(string[] args)
        {
            try
            {

                FileInfo indexDir = new FileInfo("build/index");
                FileInfo dataDir = new FileInfo("luncene");

                DateTime start = DateTime.Now;
                int numid = index(indexDir, dataDir);
                DateTime end = DateTime.Now;
                System.Console.WriteLine("Indesxing   +{0}  +file took+{1} millionseconds",numid,end-start);


            }
            catch
            { }
        }
        public static int index(FileInfo indexDir, FileInfo DataDir)
        {
          
                if (!File.Exists(DataDir.FullName)&&!Directory.Exists(DataDir.FullName))
                {
                    throw new Exception(DataDir + "does not exsit");
                }
                IndexWriter writer = new IndexWriter(DataDir,new StandardAnalyzer(),true);
                writer.SetUseCompoundFile(false);
                indexDirectory(writer,DataDir);
                int num = writer.DocCount();
                writer.Optimize();
                writer.Close();
                return num;
         
        }
        public static void indexDirectory(IndexWriter writer,FileInfo dir)
        {
            if (Directory.Exists(dir.FullName))
            {
                string[] files = Directory.GetFiles(dir.FullName);
                foreach (string str in files)
                {
                    if (Directory.Exists(str))
                    {
                        indexDirectory(writer, new FileInfo(str));
                    }
                    else
                    {
                        indexFile(writer,new FileInfo(str));
                    }
                }
            }
        }
        public static void indexFile(IndexWriter writer, FileInfo f)
        {
            if (!File.Exists(f.FullName))
            { return; }

            Console.WriteLine("Indexing +{0}", f.FullName);
            Document doc = new Document();
            doc.Add(Field.Text("contents",new StreamReader(f.FullName).ReadToEnd()));
            doc.Add(Field.Text("title",f.FullName));
            writer.AddDocument(doc);

        }

    }
}