从网上下了个操作xml的类，但不知如何新增及修改我的xml文件

Question

<?xml version="1.0" encoding="utf-8"?>
  <DCWeb>
    <HttpCompress compressionType="GZip">
      <IncludedMimeTypes>
        <!--我要在这里新增或删除这个：<add mime="text/html" />-->
      </IncludedMimeTypes>
    </HttpCompress>
  </DCWeb>不知如何制作？
类如下：
public class XmlUtility
     {
         protected string strXmlFile;
         protected XmlDocument objXmlDoc = new XmlDocument();
 
         public XmlUtility(string XmlFile)
         {
             try
             {
                if (!File.Exists(XmlFile))
                {
                    CreatXmlFile(XmlFile);
                }
                 objXmlDoc.Load(XmlFile);
 
             }
             catch (System.Exception ex)
             {
                 throw ex;
             }
             strXmlFile = XmlFile;
         }
         protected void CreatXmlFile(string file)
         {
             XmlTextWriter writer = new
             XmlTextWriter(file, Encoding.UTF8);
 
             // start writing!
             writer.WriteStartDocument();
             writer.WriteStartElement("Root");
             writer.WriteEndElement();
             writer.WriteEndDocument();
             writer.Close();
         }
         /// <summary>
         /// 查找数据。返回一个DataSet 多条 
         /// </summary>
         /// <param name="XmlPathNode">结点路径</param>
         /// <returns></returns>
         public DataSet GetData(string XmlPathNode)
         {
             //查找数据。返回一个DataSet 
             DataSet ds = new DataSet();
             //=========多个=================
             foreach(XmlNode xmlnode in objXmlDoc.SelectNodes(XmlPathNode))
             {
                 StringReader read = new StringReader(xmlnode.OuterXml);
                 ds.ReadXml(read);
             }
             //==============================
             return ds;
         }
         /// <summary>
         /// 查找数据。返回一个DataSet 单条
         /// </summary>
         /// <param name="XmlPathNode"></param>
         /// <returns></returns>
         public DataSet GetDataSingle(string XmlPathNode)
         {
             //查找数据。返回一个DataSet 
             DataSet ds = new DataSet();
             //==========单个================
             StringReader read = new StringReader(objXmlDoc.SelectSingleNode(XmlPathNode).OuterXml);
             ds.ReadXml(read);
             //==============================
             return ds;
         }
         /// <summary>
         /// 更新节点内容
         /// </summary>
         /// <param name="XmlPathNode"></param>
         /// <param name="Content"></param>
         public void Replace(string XmlPathNode, string Content)
         {
             //更新节点内容。 
             objXmlDoc.SelectSingleNode(XmlPathNode).InnerText = Content;
         }
         /// <summary>
         /// 删除一个节点
         /// </summary>
         /// <param name="Node"></param>
         public void Delete(string Node)
         {
             //删除一个节点。 
             string mainNode = Node.Substring(0, Node.LastIndexOf("/"));
             objXmlDoc.SelectSingleNode(mainNode).RemoveChild(objXmlDoc.SelectSingleNode(Node));
         }
         /// <summary>
         /// 插入一个节点和此节点的一子节点
         /// </summary>
         /// <param name="MainNode"></param>
         /// <param name="ChildNode"></param>
         /// <param name="Element"></param>
         /// <param name="Content"></param>
         public void InsertNode(string MainNode, string ChildNode, string Element, string Content)
         {
             //插入一个节点和此节点的一子节点。 
             XmlNode objRootNode = objXmlDoc.SelectSingleNode(MainNode);
             XmlElement objChildNode = objXmlDoc.CreateElement(ChildNode);
             objRootNode.AppendChild(objChildNode);
             XmlElement objElement = objXmlDoc.CreateElement(Element);
             objElement.InnerText = Content;
             objChildNode.AppendChild(objElement);
         }
         /// <summary>
         /// 插入一个节点,带一属性
         /// </summary>
         /// <param name="MainNode"></param>
         /// <param name="Element"></param>
         /// <param name="Attrib"></param>
         /// <param name="AttribContent"></param>
         /// <param name="Content"></param>
         public void InsertElement(string MainNode, string Element, string Attrib, string AttribContent, string Content)
         {
             //插入一个节点,带一属性。 
             XmlNode objNode = objXmlDoc.SelectSingleNode(MainNode);
             XmlElement objElement = objXmlDoc.CreateElement(Element);
             objElement.SetAttribute(Attrib, AttribContent);
             objElement.InnerText = Content;
             objNode.AppendChild(objElement);
         }
         /// <summary>
         /// 插入一个节点,不带属性
         /// </summary>
         /// <param name="MainNode"></param>
         /// <param name="Element"></param>
         /// <param name="Content"></param>
         public void InsertElement(string MainNode, string Element, string Content)
         {
             XmlNode objNode = objXmlDoc.SelectSingleNode(MainNode);
             XmlElement objElement = objXmlDoc.CreateElement(Element);
             objElement.InnerText = Content;
             objNode.AppendChild(objElement);
         }
         /// <summary>
         /// 保存文件
         /// </summary>
         public void Save()
         {
             //保存文件。 
             try
             {
                 objXmlDoc.Save(strXmlFile);
             }
             catch (System.Exception ex)
             {
                 throw ex;
             }
             objXmlDoc = null;
         }
     } 

Answer 1

   XmlUtility xmlUtil = new XmlUtility("test.xml");   // 添加：
   xmlUtil.InsertElement("DCWeb/HttpCompress/IncludedMimeTypes", "add", "mine", "text/html", "");
   xmlUtil.Save();
   
   // 删除：
   xmlUtil.Delete("DCWeb/HttpCompress/IncludedMimeTypes/add");
   xmlUtil.Save();

Answer 2

  xmlUtil.InsertElement("DCWeb/HttpCompress/IncludedMimeTypes", "add", "mine", "text/html", ""); 
这么写，出错啊，在InsertElement方法的objNode.AppendChild(objElement);，说未将对象引用设置到对象的实例。

Answer 3

<?xml version="1.0" encoding="utf-8"?> 
<DCWeb> 
     <HttpCompress compressionType="GZip"> 
       <IncludedMimeTypes> 这个XML结构没有变吧。DCWeb/HttpCompress/IncludedMimeTypes 是个XPath，印射XML结构。

Answer 4

在InsertElement方法的objNode.AppendChild(objElement);，说未将对象引用设置到对象的实例。就是用“DCWeb/HttpCompress/IncludedM”没有查到这个节点。你查查你的XML是不是你开始写的那样？

Answer 5

其实 这个xml是web.config
开头是:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
      <sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
        <section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication" />
        <sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
          <section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="Everywhere" />
          <section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication" />
          <section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication" />
        </sectionGroup>
      </sectionGroup>
    </sectionGroup>
    <sectionGroup name="DCWeb">
      <section name="HttpCompress" type="DC.Web.HttpCompress.Configuration,DC.Web.HttpCompress" />
    </sectionGroup>
  </configSections>
  <DCWeb>
    <HttpCompress compressionType="GZip">
      <IncludedMimeTypes>
        <!--<add mime="text/html" />-->
      </IncludedMimeTypes>
    </HttpCompress>
  </DCWeb>
........

Answer 6

 public class Class2
    {
        public Class2()
        {
        }
        //写用户聊天内容到XML
        //==================================================================================================================
        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.Read)]
        public static void writeXML(string username, string id, string content,string value,string datetime,string contentURL)
        {
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load(contentURL);
            XmlNode xmlNode = xmlDoc.SelectSingleNode("content");
            XmlElement el = xmlDoc.CreateElement("contents"); //添加节点 
            el.SetAttribute("name", username); //添加节点的属性 
            el.SetAttribute("id", id);
            el.SetAttribute("content", content);
            el.SetAttribute("toname",value);
            el.SetAttribute("datetime",datetime);
            el.SetAttribute("biaoji","0");
            xmlNode.AppendChild(el);
            xmlDoc.Save(contentURL);
        }         
        //读聊天纪录
        //==================================================================================================================
        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.Read)]
        public static List<string> readerContentXML(string id,string contentURL)
        {
            List<string> listContent = new List<string>();
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load(contentURL);
            XmlNode xmlNode = xmlDoc.SelectSingleNode("content");
            XmlNodeList xmlNodeList = xmlNode.ChildNodes;
            foreach (XmlNode xn in xmlNodeList)
            {
                XmlElement xmlElement = (XmlElement)xn;
                if (xmlElement.GetAttribute("biaoji").Equals("0"))
                {
                    //群聊
                    if (xmlElement.GetAttribute("toname") == "")
                    {
                        listContent.Add(xmlElement.GetAttribute("name") + "|" + xmlElement.GetAttribute("content"));
                        //xmlElement.Attributes();
                        xmlElement.RemoveAttributeAt(5);
                        
                        
                    }                    //判断是不是对某个人说
                    else if (xmlElement.GetAttribute("toname") == id)
                    {
                        listContent.Add(xmlElement.GetAttribute("name") + "对您" + "|" + xmlElement.GetAttribute("content"));
                        // xmlElement.Value("biaoji", "1");
                    }
                }
                else
                {
                    continue;
                }
            }
            xmlDoc.Save(contentURL);
            return listContent;
        }
        //读用户
        //==================================================================================================================
        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.Read)]
        public static List<string> readerXML(string usersURL)
        {
            List<string> liststring = new List<string>();
            XmlDocument xmlDocument = new XmlDocument();
            xmlDocument.Load(usersURL);
            XmlNode xmlNode = xmlDocument.SelectSingleNode("users");
            XmlNodeList xmlNodeList = xmlNode.ChildNodes;
            foreach (XmlNode xnf in xmlNodeList)
            {
                XmlElement xe = (XmlElement)xnf; 
                liststring.Add(xe.GetAttribute("name")+"|"+xe.GetAttribute("id"));
            }
            return liststring;          
        }
        //用户离开，删除用户XML
        //==================================================================================================================
        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.Read)]
        public static void delectXML(string username,string usersURL)
        {
            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load(usersURL);
            XmlNode xmlNode = xmlDoc.SelectSingleNode("users");
            XmlNodeList xmlNodeList = xmlNode.ChildNodes;
            foreach (XmlNode xn in xmlNodeList)
            {
                XmlElement xe = (XmlElement)xn;
                if (xe.GetAttribute("name")==username)
                {
                    xmlNode.RemoveChild(xn);
                }
            }
            xmlDoc.Save(usersURL);
        }
        //删除用户自己聊天纪录
        [Ajax.AjaxMethod(Ajax.HttpSessionStateRequirement.Read)]
        public static void delectContenXML(string username,string contentURL)
        {                    List<string> lists = new List<string>();            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.Load(contentURL);
            XmlNode xmlNode = xmlDoc.SelectSingleNode("content");
            XmlNodeList xmlNodeList = xmlNode.ChildNodes;
            int flag = xmlNodeList.Count;
            for (int i = flag-1; i >=0; i--)
            {
                XmlNode xn = xmlNodeList[i];
                XmlElement xe = (XmlElement)xn;
                if (xe.GetAttribute("name") == username)
                {
                    xmlNode.RemoveChild(xn);
                }            }
            xmlDoc.Save(contentURL);
        }    }
}
这个都有了

Answer 7

找到了，原来开头少了configuration,没看到，唉，tks fangxinggood

Answer 8

具体的忘记了
参考下msdn的XmlDocument和XmlElement这两个的说明就能搞定了