public enum SortOrder : System.Enum, System.IComparable, System.IConvertible, System.IFormattable  

public RowCursor SortWorldCities(FeatureClass worldCitiesTable)
{
  using (FeatureClassDefinition featureClassDefinition = worldCitiesTable.GetDefinition())
  {
    Field countryField = featureClassDefinition.GetFields()
      .First(x => x.Name.Equals("COUNTRY_NAME"));
    Field cityNameField = featureClassDefinition.GetFields()
      .First(x => x.Name.Equals("CITY_NAME"));

    // Create SortDescription for Country field
    SortDescription countrySortDescription = new SortDescription(countryField);
    countrySortDescription.CaseSensitivity = CaseSensitivity.Insensitive;
    countrySortDescription.SortOrder = SortOrder.Ascending;

    // Create SortDescription for City field
    SortDescription citySortDescription = new SortDescription(cityNameField);
    citySortDescription.CaseSensitivity = CaseSensitivity.Insensitive;
    citySortDescription.SortOrder = SortOrder.Ascending;

    // Create our TableSortDescription
    TableSortDescription tableSortDescription = new TableSortDescription(
      new List<SortDescription>() { countrySortDescription, citySortDescription });

    return worldCitiesTable.Sort(tableSortDescription);
  }
}