如何把下面的这段xml写成xmlDoducment对象

Question

<Carts>
<Message id="6a056d12b224797f427d9dbf19c1b7d1">
<CPReq id="CPReq">
<version>1.0.1</version>
<date>20080722 09:32:13</date>
<instId>ALIPAY</instId>
<certId>ALIPAY2007072400</certId>
<serialNo>2200807220000224599</serialNo>
<signNo>10100530000027768E8B2079CC54CC55AD23FF372D0F5</signNo>
<charge>0</charge>
<amount>102</amount>
<currency>156</currency>
</CPReq>
      </Message>
</Carts>

Answer 1

仅供参考c# code：        #region 操作XML的方法F2CreateXML、F2LoadXML、F2CreateAttr、F2CreateNode        /// <summary>
        /// 创建System.Xml.XmlDocument
        /// </summary>
        /// <param name="xmlFileName">XML文件名称</param>
        /// <returns></returns>
        public XmlDocument F2CreateXML(string xmlFileName)
        {
            XmlDocument xmlDoc = new XmlDocument();
            XmlNode xmlNode;            //加入XML的声明段落
            xmlNode = xmlDoc.CreateNode(XmlNodeType.XmlDeclaration, "", "");
            xmlNode.InnerText += " encoding=\"GB2312\"";            xmlDoc.AppendChild(xmlNode);            //加入根元素IP
            xmlNode = xmlDoc.CreateElement("", "IP", "");
            //加入IP属性
            XmlAttribute ipName = xmlDoc.CreateAttribute("IP");
            ipName.Value = F2GetIp();
            xmlNode.Attributes.Append(ipName);
            //加入MAC属性
            XmlAttribute macName = xmlDoc.CreateAttribute("MAC");
            macName.Value = F2GetMac();
            xmlNode.Attributes.Append(macName);
            
            xmlDoc.AppendChild(xmlNode);            //保存创建好的XML文档
            xmlDoc.Save(xmlFileName);            return xmlDoc;
        }        /// <summary>
        /// 调用System.Xml.XmlDocument
        /// </summary>
        /// <param name="xmlFileName">XML文件名称</param>
        /// <returns></returns>
        public XmlDocument F2LoadXML(string xmlFileName)
        {
            if (File.Exists(xmlFileName))
            {
                XmlDocument xmlDoc = new XmlDocument();
                xmlDoc.Load(xmlFileName);                return xmlDoc;
            }
            else
            {
                return F2CreateXML(xmlFileName);
            }
        }        /// <summary>
        /// 创建System.Xml.XmlAttribute
        /// </summary>
        /// <param name="xmlDoc">要修改的XmlDocument文件</param>
        /// <param name="xmlNode">要修改的节点</param>
        /// <param name="attrName">XmlAttribute的名称</param>
        /// <param name="attrValue">XmlAttribute的值</param>
        /// <returns>XmlAttribute</returns>
        public XmlAttribute F2CreateAttr(XmlDocument xmlDoc, XmlNode xmlNode, string attrName, string attrValue)
        {
            XmlAttribute xmlAttr = xmlDoc.CreateAttribute(attrName);
            xmlAttr.Value = attrValue;            xmlNode.Attributes.Append(xmlAttr);            return xmlAttr;
        }        /// <summary>
        /// 创建System.Xml.XmlNode
        /// </summary>
        /// <param name="xmlDoc">XmlDocument文档</param>
        /// <param name="xmlAttrName">属性名称数组</param>
        /// <param name="xmlAttrValue">属性值数组</param>
        /// <returns>XmlNode</returns>
        public XmlNode F2CreateNode(XmlDocument xmlDoc, String[] xmlAttrName, string[] xmlAttrValue)
        {
            XmlNode aNode = xmlDoc.CreateElement("ERROR");
            XmlAttribute[] aValue = new XmlAttribute[xmlAttrValue.Length];
            for (int i = 0; i < xmlAttrName.Length; i++)
            {
                aValue[i] = xmlDoc.CreateAttribute(xmlAttrName[i]);
                aValue[i].Value = xmlAttrValue[i];                aNode.Attributes.Append(aValue[i]);            }
            xmlDoc.FirstChild.NextSibling.AppendChild(aNode);            return aNode;
        }
        #endregion

Answer 2

string _Temp = "<Carts>";
            _Temp += "<Message id=\"6a056d12b224797f427d9dbf19c1b7d1\">";
            _Temp += "<CPReq id=\"CPReq\">";
            _Temp += "<version>1.0.1 </version>";
            _Temp += "<date>20080722 09:32:13 </date>";
            _Temp += "<instId>ALIPAY </instId>";
            _Temp += "<certId>ALIPAY2007072400 </certId>";
            _Temp += "<serialNo>2200807220000224599 </serialNo>";
            _Temp += "<signNo>10100530000027768E8B2079CC54CC55AD23FF372D0F5 </signNo>";
            _Temp += "<charge>0 </charge>";
            _Temp += "<amount>102 </amount>";
            _Temp += "<currency>156 </currency>";
            _Temp += "</CPReq>";
            _Temp += "</Message>";
            _Temp += "</Carts>";
            System.Xml.XmlDocument _Xml = new System.Xml.XmlDocument();
            _Xml.LoadXml(_Temp);                   MessageBox.Show(_Xml["Carts"]["Message"].Attributes[0].Value);直接就可以打开

Answer 3

还有一个问题，
我项目中涉及的报文（XML）格式有20-30个，每个都不同。
我总不能写死格式，以后不改吧。所以怎么定义这些格式(DTD吗)，然后以DTD为模板写入数据，变成XML文件或XMLDocutment？