XmlHelper

using System;
    using System.Collections.Generic;
    using System.Data;
    using System.IO;
    using System.Xml;
    using System.Xml.XPath;

 public class XmlHelper
    {
        private XPathNavigator nav;
        private XmlNode node;
        private XPathNodeIterator NodeIter;
        protected XmlDocument objXmlDoc = new XmlDocument();
        private string strExpression;
        protected string strXmlFile;

   public XmlHelper(string XmlFile)
    {
        try
          {
             this.objXmlDoc.Load(XmlFile);
            }
            catch (Exception ex)
            {
                throw ex;
            }
            this.strXmlFile = XmlFile;
        }

    public void Delete(string Node)
        {
            string mainNode = Node.Substring(0, Node.LastIndexOf("/"));
            this.objXmlDoc.SelectSingleNode(mainNode).RemoveChild(this.objXmlDoc.SelectSingleNode(Node));
        }

        public void DeleteChildren(string Node)
        {
            this.objXmlDoc.SelectSingleNode(Node).RemoveAll();
        }

   public DataView GetData(string XmlPathNode)
        {
            DataSet ds = new DataSet();
            this.nav = this.objXmlDoc.CreateNavigator();
            this.nav = this.nav.SelectSingleNode(XmlPathNode);
            if (this.nav == null)
            {
                throw new Exception("没有找到结点");
            }
            StringReader read = new StringReader(this.nav.get_OuterXml());
            ds.ReadXml(read);
            if (ds.Tables.Count > 0)
            {
                return ds.Tables[0].DefaultView;
            }
            return null;
        }

  public string GetElementValue(string MainNode)
        {
            this.nav = this.objXmlDoc.CreateNavigator();
            this.strExpression = string.Format("{0}", MainNode);
            this.nav = this.nav.SelectSingleNode(this.strExpression);
            return this.nav.get_Value();
        }

        public string GetElementValue(string MainNode, string Element)
        {
            this.nav = this.objXmlDoc.CreateNavigator();
            this.strExpression = string.Format("{0}/{1}", MainNode, Element);
            this.nav = this.nav.SelectSingleNode(this.strExpression);
            return this.nav.get_Value();
        }

  public string GetNodeAttrValue(string MainNode, string Attr)
        {
            this.nav = this.objXmlDoc.CreateNavigator();
            this.strExpression = string.Format("{0}@{1}", MainNode, Attr);
            this.nav.SelectSingleNode(this.strExpression);
            return this.nav.get_Value();
        }

        public List<string> GetSubNodes(string MainNode)
        {
            List<string> lst = new List<string>();
            this.nav = this.objXmlDoc.CreateNavigator();
            this.nav = this.nav.SelectSingleNode(MainNode);
            this.NodeIter = this.nav.SelectChildren(XPathNodeType.Element);
            foreach (XPathNavigator n in this.NodeIter)
            {
                lst.Add(n.get_Value());
            }
            return lst;
        }

  public void InsertElement(string MainNode, string Element, string Content)
        {
            XmlNode objNode = this.objXmlDoc.SelectSingleNode(MainNode);
            XmlElement objElement = this.objXmlDoc.CreateElement(Element);
            objElement.InnerText = Content;
            objNode.AppendChild(objElement);
        }

        public void InsertElement(string MainNode, string Element, string Attrib, string AttribContent, string Content)
        {
            XmlNode objNode = this.objXmlDoc.SelectSingleNode(MainNode);
            XmlElement objElement = this.objXmlDoc.CreateElement(Element);
            objElement.SetAttribute(Attrib, AttribContent);
            objElement.InnerText = Content;
            objNode.AppendChild(objElement);
        }

        public void InsertNode(string MainNode, string ChildNode, string Element, string Content)
        {
            XmlNode objRootNode = this.objXmlDoc.SelectSingleNode(MainNode);
            XmlElement objChildNode = this.objXmlDoc.CreateElement(ChildNode);
            objRootNode.AppendChild(objChildNode);
            XmlElement objElement = this.objXmlDoc.CreateElement(Element);
            objElement.InnerText = Content;
            objChildNode.AppendChild(objElement);
        }

  public bool IsExists(string Node)
        {
            try
            {
                if (this.objXmlDoc.SelectSingleNode(Node) == null)
                {
                    return false;
                }
                return true;
            }
            catch (Exception)
            {
                return false;
            }
        }

   public void RemoveAll(string Node)
        {
            XmlNodeList xnl = this.objXmlDoc.SelectNodes(Node);
            string mainNode = Node.Substring(0, Node.LastIndexOf("/"));
            foreach (XmlNode xn in xnl)
            {
                xn.RemoveAll();
            }
        }

        public void Replace(string XmlPathNode, string Content)
        {
            this.objXmlDoc.SelectSingleNode(XmlPathNode).InnerText = Content;
        }

        public void Save()
        {
            try
            {
                this.objXmlDoc.Save(this.strXmlFile);
            }
            catch (Exception ex)
            {
                throw ex;
            }
            this.objXmlDoc = null;
        }
    }
}