操作XML的类-XmlHelper

        #region 公共变量
        XmlDocument xmldoc;
        XmlNode xmlnode;
        XmlElement xmlelem;
        #endregion

        #region 创建Xml文档
        /// <summary>
        /// 创建一个带有根节点的Xml文件
        /// </summary>
        /// <param name="FileName">Xml文件名称</param>
        /// <param name="rootName">根节点名称</param>
        /// <param name="Encode">编码方式:gb2312，UTF-8等常见的</param>
        /// <param name="DirPath">保存的目录路径</param>
        /// <returns></returns>
        public bool CreateXmlDocument(string FileName, string rootName, string Encode)
        {
            try
            {
                xmldoc = new XmlDocument();
                XmlDeclaration xmldecl;
                xmldecl = xmldoc.CreateXmlDeclaration("1.0", Encode, null);
                xmldoc.AppendChild(xmldecl);
                xmlelem = xmldoc.CreateElement("", rootName, "");
                xmldoc.AppendChild(xmlelem);
                xmldoc.Save(FileName);
                return true;
            }
            catch (Exception e)
            {
                return false;
                throw new Exception(e.Message);
            }
        }

        #endregion

        #region 常用操作方法(增删改)
        /// <summary>
        /// 插入一个节点和它的若干子节点
        /// </summary>
        /// <param name="XmlFile">Xml文件路径</param>
        /// <param name="NewNodeName">插入的节点名称</param>
        /// <param name="HasAttributes">此节点是否具有属性，True为有，False为无</param>
        /// <param name="fatherNode">此插入节点的父节点</param>
        /// <param name="htAtt">此节点的属性，Key为属性名，Value为属性值</param>
        /// <param name="htSubNode">子节点的属性，Key为Name,Value为InnerText</param>
        /// <returns>返回真为更新成功，否则失败</returns>
        public bool InsertNode(string XmlFile, string NewNodeName, bool HasAttributes, string fatherNode, Hashtable htAtt, Hashtable htSubNode)
        {
            try
            {
                xmldoc = new XmlDocument();
                xmldoc.Load(XmlFile);
                XmlNode root = xmldoc.SelectSingleNode(fatherNode);
                xmlelem = xmldoc.CreateElement(NewNodeName);

                if (htAtt != null && HasAttributes)//若此节点有属性，则先添加属性
                {
                    SetAttributes(xmlelem, htAtt);

                    SetNodes(xmlelem.Name, xmldoc, xmlelem, htSubNode);//添加完此节点属性后，再添加它的子节点和它们的InnerText

                }
                else
                {
                    SetNodes(xmlelem.Name, xmldoc, xmlelem, htSubNode);//若此节点无属性，那么直接添加它的子节点
                }

                root.AppendChild(xmlelem);
                xmldoc.Save(XmlFile);

                return true;
            }
            catch (Exception e)
            {

                throw new Exception(e.Message);

            }
        }
        /// <summary>
        /// 更新节点
        /// </summary>
        /// <param name="XmlFile">Xml文件路径</param>
        /// <param name="fatherNode">需要更新节点的上级节点</param>
        /// <param name="htAtt">需要更新的属性表，Key代表需要更新的属性，Value代表更新后的值</param>
        /// <param name="htSubNode">需要更新的子节点的属性表，Key代表需要更新的子节点名字Name,Value代表更新后的值InnerText</param>
        /// <returns>返回真为更新成功，否则失败</returns>
        public bool UpdateNode(string XmlFile, string fatherNode, Hashtable htAtt, Hashtable htSubNode)
        {
            try
            {
                xmldoc = new XmlDocument();
                xmldoc.Load(XmlFile);
                XmlNodeList root = xmldoc.SelectSingleNode(fatherNode).ChildNodes;
                UpdateNodes(root, htAtt, htSubNode);
                xmldoc.Save(XmlFile);
                return true;
            }
            catch (Exception e)
            {
                throw new Exception(e.Message);
            }
        }

        /// <summary>
        /// 删除指定节点下的子节点
        /// </summary>
        /// <param name="XmlFile">Xml文件路径</param>
        /// <param name="fatherNode">制定节点</param>
        /// <returns>返回真为更新成功，否则失败</returns>
        public bool DeleteNodes(string XmlFile, string fatherNode)
        {
            try
            {
                xmldoc = new XmlDocument();
                xmldoc.Load(XmlFile);
                xmlnode = xmldoc.SelectSingleNode(fatherNode);
                xmlnode.RemoveAll();
                xmldoc.Save(XmlFile);
                return true;
            }
            catch (XmlException xe)
            {
                throw new XmlException(xe.Message);
            }
        }
        #endregion

        #region 私有方法
        /// <summary>
        /// 设置节点属性
        /// </summary>
        /// <param name="xe">节点所处的Element</param>
        /// <param name="htAttribute">节点属性，Key代表属性名称，Value代表属性值</param>
        private void SetAttributes(XmlElement xe, Hashtable htAttribute)
        {
            foreach (DictionaryEntry de in htAttribute)
            {
                xe.SetAttribute(de.Key.ToString(), de.Value.ToString());
            }
        }
        /// <summary>
        /// 增加子节点到根节点下
        /// </summary>
        /// <param name="rootNode">上级节点名称</param>
        /// <param name="XmlDoc">Xml文档</param>
        /// <param name="rootXe">父根节点所属的Element</param>
        /// <param name="SubNodes">子节点属性，Key为Name值，Value为InnerText值</param>
        private void SetNodes(string rootNode, XmlDocument XmlDoc, XmlElement rootXe, Hashtable SubNodes)
        {
            foreach (DictionaryEntry de in SubNodes)
            {
                xmlnode = XmlDoc.SelectSingleNode(rootNode);
                XmlElement subNode = XmlDoc.CreateElement(de.Key.ToString());
                subNode.InnerText = de.Value.ToString();
                rootXe.AppendChild(subNode);
            }
        }
        /// <summary>
        /// 更新节点属性和子节点InnerText值
        /// </summary>
        /// <param name="root">根节点名字</param>
        /// <param name="htAtt">需要更改的属性名称和值</param>
        /// <param name="htSubNode">需要更改InnerText的子节点名字和值</param>
        private void UpdateNodes(XmlNodeList root, Hashtable htAtt, Hashtable htSubNode)
        {
            foreach (XmlNode xn in root)
            {
                xmlelem = (XmlElement)xn;
                if (xmlelem.HasAttributes)//如果节点如属性，则先更改它的属性
                {
                    foreach (DictionaryEntry de in htAtt)//遍历属性哈希表
                    {
                        if (xmlelem.HasAttribute(de.Key.ToString()))//如果节点有需要更改的属性
                        {
                            xmlelem.SetAttribute(de.Key.ToString(), de.Value.ToString());//则把哈希表中相应的值Value赋给此属性Key
                        }
                    }
                }
                if (xmlelem.HasChildNodes)//如果有子节点，则修改其子节点的InnerText
                {
                    XmlNodeList xnl = xmlelem.ChildNodes;
                    foreach (XmlNode xn1 in xnl)
                    {
                        XmlElement xe = (XmlElement)xn1;
                        foreach (DictionaryEntry de in htSubNode)
                        {
                            if (xe.Name == de.Key.ToString())//htSubNode中的key存储了需要更改的节点名称，
                            {
                                xe.InnerText = de.Value.ToString();//htSubNode中的Value存储了Key节点更新后的数据
                            }
                        }
                    }
                }

            }
        }
        #endregion
    }