public Uri GetUri(int limit, int page, DateTime?begin, DateTime?end) { var builder = new UriBuilder("https://", "ws.audioscrobbler.com/2.0"); var query = new List <String>() { "method=user.getrecenttracks", "user="******"api_key=" + this.apiKey, "format=json", "extended=1", "limit=" + limit.ToString(), "page=" + page.ToString(), }; if (begin != null) { query.Add("from=" + UnixTime.Format(begin.Value)); } if (end != null) { query.Add("to=" + UnixTime.Format(end.Value)); } builder.Query = String.Join("&", query); return(builder.Uri); }