/// <summary>
/// Adds an attribute index to an existing table, feature class, shapefile, coverage, or attributed relationship class.
/// </summary>
/// <param name="source">The source.</param>
/// <param name="name">
/// The name of the new index. An index name is necessary when adding an index to geodatabase feature
/// classes and tables. For other data types, such as shapefiles and coverage feature classes, index names cannot be
/// specified.
/// </param>
/// <param name="fields">
/// The list of fields that can participate in an attribute index. Any number of these fields can be
/// part of the index.
/// </param>
/// <param name="unique">if set to <c>true</c> when the values in the index are unique.</param>
/// <param name="ascending">if set to <c>true</c> when the values are indexed in ascending order.</param>
/// <param name="trackCancel">The track cancel.</param>
/// <param name="eventHandler">The events.</param>
public static void AddIndex(this ITable source, string name, string[] fields, bool unique, bool ascending, ITrackCancel trackCancel, IGeoProcessorEvents eventHandler)
{
AddIndex gp = new AddIndex();
gp.in_table = source;
gp.index_name = name;
gp.fields = string.Join(";", fields);
gp.unique = unique ? "UNIQUE" : "NON_UNIQUE";
gp.ascending = ascending ? "ASCENDING" : "NON_ASCENDING";
gp.Run(trackCancel, eventHandler);
}