XML文档解析，使用Linq to Xml方式操作确实很方便,好东西值得推荐

    Models.AjaxResult.BlastSearchResult blastSearchResult = new Models.AjaxResult.BlastSearchResult();

    var rssXDoc = XDocument.Load(rtPath);

    blastSearchResult.Query = rssXDoc.Descendants("Iteration_query-def").FirstOrDefault().Value;
    blastSearchResult.Length = rssXDoc.Descendants("Iteration_query-len").FirstOrDefault().Value;
    blastSearchResult.Iteration_hits = new List<Models.AjaxResult.BlastSearchResult.Hit>();

    var queryHit = (from hit in rssXDoc.Descendants("Hit")
                    select new Models.AjaxResult.BlastSearchResult.Hit
                    {

                        Hit_num = hit.Element("Hit_num").Value,

                        Hit_id = hit.Element("Hit_id").Value, //Int32.Parse

                        Hit_def = hit.Element("Hit_def").Value,

                        Hit_accession = hit.Element("Hit_accession").Value,

                        Hit_len = hit.Element("Hit_len").Value,

                        Hit_hsps = Models.AjaxResult.BlastSearchResult.Hsp.ParserXmlNode(hit.Descendants("Hit_hsps"))

                    });

更详细的语法文档：linq to xml操作XML