public static void CreateXml()

        {

            //创XML建对象

            XmlDocument doc = new XmlDocument();

            //声明根节点

            XmlElement books;

            //判断文件是否存在

            if (File.Exists("d://Test.xml"))

            {

                //该文件存在

                //加载文件

                doc.Load("d://Test.xml");

                //获得根节点

                books = doc.DocumentElement;

            }

            else//该文件不存在

            {

                //创建声明

                XmlDeclaration dec = doc.CreateXmlDeclaration("1.0", "utf-8", null);

                doc.AppendChild(dec);

                //创建根节点

                books = doc.CreateElement("EBD");

                doc.AppendChild(books);

            }

            //开始正常写入信息就可以了

            XmlElement xml = doc.CreateElement("EBM");

            books.AppendChild(xml);

            XmlElement ebmId = doc.CreateElement("EBMID");

            ebmId.InnerText = "1";

            xml.AppendChild(ebmId);

            XmlElement areaCode = doc.CreateElement("AreaCode");

            areaCode.InnerText = "360699999901";

            xml.AppendChild(areaCode);

            XmlElement startTime = doc.CreateElement("StartTime");

            startTime.InnerText = "2018-07-26 9:06:04";

            xml.AppendChild(startTime);

            XmlElement endTime = doc.CreateElement("EndTime");

            endTime.InnerText = "2018-07-26 7:22:04";

            xml.AppendChild(endTime);

            XmlElement msgType = doc.CreateElement("MsgType");

            msgType.InnerText = "1";

            xml.AppendChild(msgType);

            doc.Save("d://Test.xml");

        }

public static void UpdateXmlForEBMID(string ebmId)

        {

            XmlDocument xmlDoc = new XmlDocument();

            xmlDoc.Load("d://Test.xml");

            var xns = xmlDoc.SelectSingleNode("EBD");

            XmlNodeList xnl = xns.ChildNodes;

            foreach(XmlNode xn in xnl )

            {

                XmlElement xe = (XmlElement)xn;

                XmlNodeList xnl2 = xe.ChildNodes;

                foreach (XmlNode xn2 in xnl2)

                {

                    XmlElement xe2 = (XmlElement)xn2;

                    if (xe2.InnerText.Equals(ebmId))

                    {

                        XmlNodeList elemList = xe.GetElementsByTagName("MsgType");

                        elemList[0].InnerXml = "2";

                    }

                    break;

                }

                //break;//如果更新完了指定节点，有需要则退出循环

            }

            xmlDoc.Save("d://Test.xml");//保存的该XML文件,否则更新无效

        }

public static void ReadXMLForLog(string xmlPath,string ebmId)

        {

            XmlDocument xmlDoc = new XmlDocument();

            xmlDoc.Load("d://Test.xml");

            var xns = xmlDoc.SelectSingleNode("EBD");

            XmlNodeList xnl = xns.ChildNodes;

            Dictionary<string, string> obj = new Dictionary<string, string>();

            foreach (XmlNode xn in xnl)

            {

                XmlElement xe = (XmlElement)xn;

                XmlNodeList xnl2 = xe.ChildNodes;

                foreach (XmlNode xn2 in xnl2)

                {

                    XmlElement xe2 = (XmlElement)xn2;

                    if (xe2.InnerText.Equals("2"))

                    {

                        var objs = new {

                            EBMID = xe.GetElementsByTagName("EBMID"),

                            AreaCode = xe.GetElementsByTagName("AreaCode"),

                            StartTime= xe.GetElementsByTagName("StartTime"),

                            EndTime = xe.GetElementsByTagName("EndTime"),

                            MsgType = xe.GetElementsByTagName("MsgType"),

                        };

                        string ebmIdValue = objs.EBMID[0].InnerText;

                    }

                    break;

                }

            }

        }