C# Xml 操作

//读取
System.Xml.XmlDocument xmlDoc = new System.Xml.XmlDocument();
xmlDoc.LoadXml(xml);
XmlNode XNSpec = xmlDoc.SelectSingleNode("spec");
XmlNodeList XLlist = XNSpec.ChildNodes;  //读取所有节点

foreach (XmlNode xnnode in XLlist)
{
if (xnnode.Name.ToLower() == specname)
     {
         returnStr = xnnode.InnerText.Trim();
     }
}

// 插入
　　　　　　System.Xml.XmlDocument xmlDoc = new System.Xml.XmlDocument();
　　　　　　xmlDoc.LoadXml(xml);
                XmlNode XNSpec = xmlDoc.SelectSingleNode("spec");
                XmlNodeList XLlist = XNSpec.ChildNodes;

foreach (XmlNode xnnode in XLlist)
                {
if (xnnode.Name.ToLower() == lowspecname)
                    {
                        xnnode.InnerText = specvalue;
                        hasSetted = true;
                    }
                }

// 若没有设定过则需要添加字段
                if (!hasSetted)
                {
                    XmlElement elem = xmlDoc.CreateElement(specname);
                    elem.InnerText = specvalue;
                    XNSpec.AppendChild(elem);
                }