c#读取xml文件为什么我去掉头文件就能读到信息，有头文件读到的是空的

我的xml：
<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<stations>
  <station>
    <name>XXX</name>
    <stationCode>1</stationCode>
    <stationType>W</stationType>
    <left>1024</left>
    <top>10</top>
  </station> public void Read()
        {
            XmlDocument doc = new XmlDocument();
            doc.Load("D:/XMLFile1.xml");
            // doc.Load("D:/du.xml");
            //doc.Load("");            XmlNode xmlNode = doc.FirstChild;
            XmlNodeList xmlNodeList = xmlNode.ChildNodes;         
            List<XML> xmlList = new List<XML>();            foreach (XmlNode item in xmlNodeList)
            {
                XML myxml = new XML();
                XmlNodeList nodelist = item.ChildNodes;//获取节点里的所有子节点                foreach (XmlNode node in nodelist)
                {
                   
                    string value = node.InnerText;                    switch (node.Name)
                    {
                        case "name":
                            myxml.Name = value;
                            break;                        case "stationCode":
                            myxml.StationCode = value;
                            break;                        case "stationType":
                            myxml.StationType = value;
                            break;                        case "left":
                            myxml.Left = Convert.ToDouble(value);
                            break;                        case "top":
                            myxml.Top = Convert.ToDouble(value);
                            break;
                    }
                }
                            xmlList.Add(myxml);            }
            foreach (XML xml in xmlList)
            {
                Console.WriteLine(xml);
            }
        }