/// <summary>
/// Gets the tracks by genre.
/// </summary>
/// <param name="genreId">The genre id.</param>
/// <param name="musicSearchBy">The music search by.</param>
/// <param name="marker">The next/previous marker to get next/previous items</param>
/// <param name="locale">The locale.</param>
/// <returns></returns>
/// <exception cref="System.NullReferenceException">Genre Id cannot be null or empty</exception>
public async Task <TrackCollection> GetTracksByGenreAsync(string genreId, MusicSearchBy musicSearchBy = MusicSearchBy.SalesRank, string marker = "afterMarker=CgAAAA%3d%3d", string locale = null)
{
if (string.IsNullOrEmpty(genreId))
{
throw new NullReferenceException("Genre Id cannot be null or empty");
}
locale = string.IsNullOrEmpty(locale) ? Locale : locale;
var url = string.Format(Constants.ItemsByGenreUrlFormat, locale, genreId, "tracks", musicSearchBy.ToString(), marker);
var xml = await HttpClient.GetStringAsync(url);
var result = ParseXml <ZuneTrackSearch.feed>(xml);
if (result.entry == null)
{
return(new TrackCollection(new List <Track>()));
}
var resultList = new TrackCollection(result.entry.Select(x => new Track(x)).ToList());
resultList.ProcessLinks(result.link);
return(resultList);
}