最近运用Lucene.Net做了个全文检索。开始时用了Lucene.Net 1.9版本，按照关键字查询没有问题，加入按时间范围查询，结果没有查到数据。取出Lucene语句直接在Luke工具里查询，也没有记录出来。
我昨天发邮件请教了 雨痕 RainTrail （http://www.rainsts.net/），他回复我了，给了我一小段代码，一点思想，就开窍了。在此表示万分感谢！
用Lucene.Net 1.9我目前没有找到解决办法，还是无法实现按时间范围查询，我改用 Lucene.Net 2.0 尝试，方案一：Lucene复合语句 + 运用RangeFilter类 实现了按时间范围查询。方案二：只用Lucene复合语句，可以查到数据，但关键显示内容为null了（不知道什么原因？）。关键代码如下供大家分享：
方案一：Lucene复合语句 + 运用RangeFilter类
public ResultSet Search(int pageIndex,int PageSize,int PostTime,.....)
{
ChineseAnalyzer analyse = new ChineseAnalyzer();
StopWatch sw = new StopWatch();
//定义一个StopWatch 对象
string strlucene = ""; //lucene语句，未加入时间查询语句
.... //如 strlucene = +( +Content:手机 +Content:数码相机 -Content:销售 )
QueryParser parser = new QueryParser("Content", analyse);
Query query = parser.Parse(strlucene);
if(PostTime!=0)
{
//运用RangeFilter类
string lower = DateTime.Now.AddDays(PostTime*(-1)).ToString("yyyyMMdd");
string upper = DateTime.Now.ToString("yyyyMMdd");
RangeFilter filter = new RangeFilter("PostDateTime", lower, upper, true, true);
Hits hits = searcher.Search(query, filter);
long executionTime = sw.Peek();
ResultSet results = GetResults(hits,pageIndex,query,PageSize); //见最下面，自己构建的方法，支持分页，返回自己需要的数据集
results.ExecutionTime = executionTime;
return results;
}
else
{
Hits hits = searcher.Search(query);
long executionTime = sw.Peek();
ResultSet results = GetResults(hits,pageIndex,query,PageSize); //同上
results.ExecutionTime = executionTime;
return results;
}
}
方案二：只用Lucene复合语句
public ResultSet Search(int pageIndex,int PageSize,int PostTime,.....)
{
ChineseAnalyzer analyse = new ChineseAnalyzer();
StopWatch sw = new StopWatch(); //定义一个StopWatch 对象
string strlucene = ""; //lucene语句，加入了时间查询语句
if(PostTime!=0)
{
strposttime = " +PostDateTime:["+ DateTime.Now.AddDays(PostTime*(-1)).ToString("yyyyMMdd") + " TO " + DateTime.Now.ToString("yyyyMMdd") +"] ";
}
.... //如 strlucene = +( +Content:手机 +Content:数码相机 -Content:销售 )
QueryParser parser = new QueryParser("Content", analyse);
Query query = parser.Parse(strlucene);
Hits hits = searcher.Search(query);
long executionTime = sw.Peek();
ResultSet results = GetResults(hits,pageIndex,query,PageSize); //同上
results.ExecutionTime = executionTime;
return results;
}
private ResultSet GetResults(Hits hits,int pageIndex,Query query,int PageSize)
{
int startPosition = (pageIndex - 1) * PageSize;
int endPosition = startPosition + PageSize;
if(hits.Length() < endPosition)
{
endPosition = hits.Length();
}
return GetResults(hits,startPosition,endPosition,query);
}
private ResultSet GetResults(Hits hits, int startPosition, int endPosition, Query query)
{
ResultSet results = new ResultSet();
try
{
ChineseAnalyzer analyzer = new ChineseAnalyzer();
results.Count = hits.Length();
Highlighter highlighter = null;
ArrayList al = new ArrayList();
Result result = null;
Document doc = null;
for(int i = startPosition; i<endPosition; i++)
{
result = new Result();
doc = hits.Doc(i);
result.PostDateTime = doc.GetField("PostDateTime").StringValue();
result.UserName = doc.GetField("UserName").StringValue();
result.PostUrl = doc.GetField("PostUrl").StringValue();
result.Title = doc.GetField("Title").StringValue();
if(FragementSize > 0)
{
string text = doc.GetField("Content").StringValue();
// 高亮显示设置
SimpleHTMLFormatter simpleHTMLFormatter = new SimpleHTMLFormatter("<font color=\"red\">", "</font>");
highlighter = new Highlighter(simpleHTMLFormatter, new QueryScorer(query));
highlighter.SetTextFragmenter(new SimpleFragmenter(FragementSize));
TokenStream tokenStream = analyzer.TokenStream("Content", new StringReader(text));
result.Content = highlighter.GetBestFragment(tokenStream,text); //加入时间查询语句时，问题出于这里，被赋了null值
}
else
{
result.Content = doc.GetField("Content").StringValue();
}
result.Score = hits.Score(i);
al.Add(result);
}
results.Results = (Result[])al.ToArray(typeof(Result));
}
catch(Exception e)
{
LogError.Write("GetResult Fail:"+e.Message);
}
return results;
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