TestLucene

using System;
using Lucene.Net.Analysis.Standard;
using Lucene.Net.Documents;
using Lucene.Net.Index;
using Lucene.Net.QueryParsers;
using Lucene.Net.Search;
using Lucene.Net.Store;
using Version = Lucene.Net.Util.Version;

namespace TestProgram
{
    class Program
    {
        public class TestSim : DefaultSimilarity
        {
            public override float Tf(float freq)
            {
               return freq;
            }
        }

        public static void Main(string[] args)
        {
            var analyzer = new StandardAnalyzer(Version.LUCENE_29);
            using (var directory = new RAMDirectory())
            {
                using (var writer = new IndexWriter(directory, analyzer, IndexWriter.MaxFieldLength.UNLIMITED))
                {
                    writer.SetSimilarity(new TestSim());

                    var d = new Document();
                    d.Add(new Field("Description", "one two", Field.Store.YES, Field.Index.ANALYZED, Field.TermVector.NO));
                    writer.AddDocument(d);

                    d = new Document();
                    d.Add(new Field("Description", "one three", Field.Store.YES, Field.Index.ANALYZED, Field.TermVector.NO));
                    writer.AddDocument(d);

                    d = new Document();
                    d.Add(new Field("Description", "one blah blah blah blah one", Field.Store.YES, Field.Index.ANALYZED, Field.TermVector.NO));
                    writer.AddDocument(d);
                }

                // set up lucene searcher
                using (var searcher = new IndexSearcher(directory, false))
                {
                    var hits_limit = 1000;

                    searcher.Similarity = new TestSim();

                    var parser = new QueryParser(Version.LUCENE_29, "Description", analyzer);
                    var query = parser.Parse("one");

                    Console.WriteLine(query.GetSimilarity(searcher).GetType());

                    var hits = searcher.Search(query, null, hits_limit, Sort.RELEVANCE).ScoreDocs;

                    foreach (var hit in hits)
                    {
                        Console.WriteLine("Hit Doc: {0}", hit.Doc);
                        Console.WriteLine("Hit Score: {0}", hit.Score);

                        var d = searcher.Doc(hit.Doc);
                        Console.WriteLine("Contents: {0}", d.Get("Description"));
                        Console.WriteLine();
                    }
                }
            }
        }
    }
}