求代码:xml的读取和更新

Question

求代码，一种是读取，一种是更新。
1、读取 ShopConfig和MailSetting下面的子节点的值
2、更新 ShopConfig和MailSetting下面的子节点的值<?xml version="1.0" encoding="utf-8" ?>
<ShopConfig>
  <ShopName>商店名</ShopName>
  <ShopTitle>商店标题</ShopTitle>
  <ShopKeywords>商品,电子商务,购物</ShopKeywords>
  <ShopDesc>商店</ShopDesc>
  <SiteUrl>http://www.xxx.net/</SiteUrl>
  <ShopLogo></ShopLogo>
  <IcpNumber>沪ICP备0754664575号</IcpNumber>
  <MarketPriceRate>1.2</MarketPriceRate>
  <Rewrite>0</Rewrite>
  <SnPrefix>GSN</SnPrefix>
  <NoPicture></NoPicture>
  <StatsCode></StatsCode>
  <CookieTime>20</CookieTime>
  <DefaultStorage>1</DefaultStorage>
  <SearchKeywords>香膏,润唇膏,bb,猪油膏,香水,乳液,面膜</SearchKeywords>
  <TopNumber>8</TopNumber>
  <CommentsNumber>15</CommentsNumber>
  <RelatedNumber>6</RelatedNumber>
  <ArticleNumber>20</ArticleNumber>
  <GoodsPageZize>20</GoodsPageZize>
  <ArticlePageZize>20</ArticlePageZize>
  <ShowGoodsSn>1</ShowGoodsSn>
  <ShowBrand>1</ShowBrand>
  <ShowGoodsNumber>1</ShowGoodsNumber>
  <ShowAddTime>0</ShowAddTime>
  <ShowMarketPrice>0</ShowMarketPrice>
</ShopConfig>
<MailSetting>
  <SmtpSsl>0</SmtpSsl>
  <SmtpHost>[email protected]</SmtpHost>
  <SmtpPort>23</SmtpPort>
  <SmtpUser>rgtert4t</SmtpUser>
  <SmtpPass>sdgsg43434</SmtpPass>
  <SmtpMail>[email protected]</SmtpMail>
  <MailCharset>UTF8</MailCharset>
</MailSetting>

Answer 1

参考http://blog.csdn.net/chinajiyong/article/details/7485019

Answer 2

 WebSite web = null;
            IList<WebSite> list = new List<WebSite>();
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load(@"Websites.xml");
            XmlNode xn = xmlDoc.SelectSingleNode("Websites");
            XmlNodeList xnlChild = xn.ChildNodes;
            foreach (XmlNode xnode in xnlChild)
            {
                XmlElement xe = (XmlElement)xnode;
                XmlNodeList xnl0 = xe.ChildNodes;
                string webName = xnl0.Item(0).InnerText;
                string url = xnl0.Item(1).InnerText;                web = new WebSite(webName, url);                list.Add(web);
            }
            return list;类似