Interface for SearchJob.StatusHandler, with additional OnProgressUpdate callback.

dtSearch::Engine::ISearchStatusHandler
    dtSearch::Engine::ISearchStatusHandler2

public interface ISearchStatusHandler2 : ISearchStatusHandler;

Public Interface ISearchStatusHandler2
Inherits ISearchStatusHandler

Use SearchJob.StatusHandler to request a callback each time a document is found, and to monitor the progress of a search. Use ISearchStatusHandler2 to obtain the OnProgressUpdate callback in addition to the other callbacks that ISearchStatusHandler supports.