the number of documents that matched the search, or a negative value if the search failed.
Set the selection state of all documents in an index that match search request.
You can also use SearchJob.WantResultsAsFilter to create a SearchFilter from the results of a search. Using SearchJob.WantResultsAsFilter is more flexible than SelectItemsBySearch because you can use any of the properties of the SearchJob (search flags, FileConditions, etc.) rather than just a simple search request