C# XML操作類 XmlHelper

using System.Xml;

using System.Data;

namespace DotNet.Utilities

{

    /// <summary>

    /// Xml的操作公共類

    /// </summary>   

    public class XmlHelper

    {

        #region 字段定義

        /// <summary>

        /// XML檔案的實體路徑

        /// </summary>

        private string _filePath = string.Empty;

        /// Xml文檔

        private XmlDocument _xml;

        /// XML的根節點

        private XmlElement _element;

        #endregion

        #region 構造方法

        /// 執行個體化XmlHelper對象

        /// <param name="xmlFilePath">Xml檔案的相對路徑</param>

        public XmlHelper(string xmlFilePath)

        {

            //擷取XML檔案的絕對路徑

            _filePath = SysHelper.GetPath(xmlFilePath);

        }

        #region 建立XML的根節點

        /// 建立XML的根節點

        private void CreateXMLElement()

            //建立一個XML對象

            _xml = new XmlDocument();

            if (DirFile.IsExistFile(_filePath))

            {

                //加載XML檔案

                _xml.Load(this._filePath);

            }

            //為XML的根節點指派

            _element = _xml.DocumentElement;

        #region 擷取指定XPath表達式的節點對象

        /// 擷取指定XPath表達式的節點對象

        /// </summary>       

        /// <param name="xPath">XPath表達式,

        /// 範例1: @"Skill/First/SkillItem", 等效于 @"//Skill/First/SkillItem"

        /// 範例2: @"Table[USERNAME='a']" , []表示篩選,USERNAME是Table下的一個子節點.

        /// 範例3: @"ApplyPost/Item[@itemName='崗位編号']",@itemName是Item節點的屬性.

        /// </param>

        public XmlNode GetNode(string xPath)

            //建立XML的根節點

            CreateXMLElement();

            //傳回XPath節點

            return _element.SelectSingleNode(xPath);

        #region 擷取指定XPath表達式節點的值

        /// 擷取指定XPath表達式節點的值

        public string GetValue(string xPath)

            //傳回XPath節點的值

            return _element.SelectSingleNode(xPath).InnerText;

        #region 擷取指定XPath表達式節點的屬性值

        /// 擷取指定XPath表達式節點的屬性值

        /// <param name="attributeName">屬性名</param>

        public string GetAttributeValue(string xPath, string attributeName)

            //傳回XPath節點的屬性值

            return _element.SelectSingleNode(xPath).Attributes[attributeName].Value;

        #region 新增節點

        /// 1. 功能：新增節點。

        /// 2. 使用條件：将任意節點插入到目前Xml檔案中。

        /// <param name="xmlNode">要插入的Xml節點</param>

        public void AppendNode(XmlNode xmlNode)

            //導入節點

            XmlNode node = _xml.ImportNode(xmlNode, true);

            //将節點插入到根節點下

            _element.AppendChild(node);

        /// 2. 使用條件：将DataSet中的第一條記錄插入Xml檔案中。

        /// <param name="ds">DataSet的執行個體，該DataSet中應該隻有一條記錄</param>

        public void AppendNode(DataSet ds)

            //建立XmlDataDocument對象

            XmlDataDocument xmlDataDocument = new XmlDataDocument(ds);

            XmlNode node = xmlDataDocument.DocumentElement.FirstChild;

            AppendNode(node);

        #region 删除節點

        /// 删除指定XPath表達式的節點

        public void RemoveNode(string xPath)

            //擷取要删除的節點

            XmlNode node = _xml.SelectSingleNode(xPath);

            //删除節點

            _element.RemoveChild(node);

        #endregion //删除節點

        #region 儲存XML檔案

        /// 儲存XML檔案

        public void Save()

            //儲存XML檔案

            _xml.Save(this._filePath);

        #endregion //儲存XML檔案

        #region 靜态方法

        #region 建立根節點對象

        /// 建立根節點對象

        /// <param name="xmlFilePath">Xml檔案的相對路徑</param>       

        private static XmlElement CreateRootElement(string xmlFilePath)

            //定義變量，表示XML檔案的絕對路徑

            string filePath = "";

            filePath = SysHelper.GetPath(xmlFilePath);

            //建立XmlDocument對象

            XmlDocument xmlDocument = new XmlDocument();

            //加載XML檔案

            xmlDocument.Load(filePath);

            //傳回根節點

            return xmlDocument.DocumentElement;

        public static string GetValue(string xmlFilePath, string xPath)

            //建立根對象

            XmlElement rootElement = CreateRootElement(xmlFilePath);

            return rootElement.SelectSingleNode(xPath).InnerText;

        public static string GetAttributeValue(string xmlFilePath, string xPath, string attributeName)

            return rootElement.SelectSingleNode(xPath).Attributes[attributeName].Value;

        public static void SetValue(string xmlFilePath, string xPath, string newtext)

            //string path = SysHelper.GetPath(xmlFilePath);

            //var queryXML = from xmlLog in xelem.Descendants("msg_log")

            //               //所有名字為Bin的記錄

            //               where xmlLog.Element("user").Value == "Bin"

            //               select xmlLog;

            //foreach (XElement el in queryXML)

            //{

            //    el.Element("user").Value = "LiuBin";//開始修改

            //}

            //xelem.Save(path);

    }

}