public event EventHandler<OperationProgressEventArgs> OperationProgressChanged

Public Event OperationProgressChanged As EventHandler(Of OperationProgressEventArgs)

public:
 event EventHandler<OperationProgressEventArgs^>^ OperationProgressChanged {
	void add (EventHandler<OperationProgressEventArgs^>^ value);
	void remove (EventHandler<OperationProgressEventArgs^>^ value);
}

member OperationProgressChanged : IEvent<EventHandler<OperationProgressEventArgs>,
    OperationProgressEventArgs>

string indexFolder = @"c:\MyIndex\";
string documentsFolder = @"c:\MyDocuments\";

// Creating an index
Index index = new Index(indexFolder);

// Subscribing to the event
index.Events.OperationProgressChanged += (sender, args) =>
{
    Console.WriteLine("Last processed: " + args.LastDocumentPath);
    Console.WriteLine("Result: " + args.LastDocumentStatus);
    Console.WriteLine("Processed documents: " + args.TotalDocuments);
    Console.WriteLine("Progress percentage: " + args.ProgressPercentage);
};

// Indexing documents from the specified folder
index.Add(documentsFolder);