C# 把内容写入xml文件

Question

xml文件格式
<?xml version="1.0" encoding="gb2312"?> 
<pics>
    <subject pic="xx.jpg" link ="url" />
</pics>
如何方式，增加内容如
<?xml version="1.0" encoding="gb2312"?> 
<pics>
    <subject pic="新写入.jpg" link ="新写入url" />
    <subject pic="xx.jpg" link ="url" />
</pics>

Answer 1

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(Server.MapPath("~/test.xml"));
XmlElement newElement = xmlDoc.CreateElement("subject");
newElement.SetAttribute("pic", "新写入.jpg");
newElement.SetAttribute("link", "新url");
xmlDoc.DocumentElement.AppendChild(newElement);
xmlDoc.Save(Server.MapPath("~/test.xml"));

Answer 2

XmlDocument xmlDoc = new XmlDocument();
        xmlDoc.Load("xml文件路径");
        XmlNodeList subjectNodeList = xmlDoc.SelectNodes("subject");
        XmlNode subjectNode = null;
        for (int i = 0; i < subjectNodeList.Count; i += 1)
        {
            if (subjectNodeList[i].Attributes["pic"].InnerText == "xx.jpg")
            {
                subjectNode = subjectNodeList[i];
            }
        }        XmlNode newSubjectNode = xmlDoc.CreateElement("subject");
        xmlDoc.InsertAfter(newSubjectNode, subjectNode);

Answer 3

如果要确保插入在最前面，可以用
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(Server.MapPath("~/test.xml"));
XmlElement newElement = xmlDoc.CreateElement("subject");
newElement.SetAttribute("pic", "新写入.jpg");
newElement.SetAttribute("link", "新url");
xmlDoc.DocumentElement.InsertBefore(newElement, xmlDoc.DocumentElement.ChildNodes[0]);
xmlDoc.Save(Server.MapPath("~/test.xml"));

Answer 4

            string path = @"c:\test.xml";
            XDocument document = XDocument.Load(path);
            document.Element("pics").AddFirst(new XElement("subject",
                new XAttribute("pic", "新写入.jpg"),
                new XAttribute("link", "新写入url")));            document.Save(path);

Answer 5

XmlDocument xmlDoc = new XmlDocument();
        xmlDoc.Load(Server.MapPath("~/test.xml"));
        XmlElement newElement = xmlDoc.CreateElement("subject");
        newElement.SetAttribute("pic", "新写入.jpg");
        newElement.SetAttribute("link", "新url");
        xmlDoc.DocumentElement.InsertBefore(newElement, xmlDoc.DocumentElement.ChildNodes[0]);
        xmlDoc.Save(Server.MapPath("~/test.xml"));