Apache Lucene.Net 2.4.0 Class Library API

TermFreqVector.IndexOf Method 

Return an index in the term numbers array returned from

getTerms
at which the term with the specified
term
appears. If this term does not appear in the array, return -1.

int IndexOf(
   string term
);

See Also

TermFreqVector Interface | Lucene.Net.Index Namespace