如何使用System.XML在C#中注释XML文件的一行

Question

我需要使用System.XML属性注释和取消注释此XML文件的第4行:

<?xml version="1.0" encoding="utf-8"?>
    <configuration>    
        <system.web>
            <customErrors mode="On" defaultRedirect="som_url_here" />
        </system.web>
    </configuration>

期望的输出:

<!-- <customErrors mode="On" defaultRedirect="som_url_here" /> -->

不使用文件阅读器就可以实现这一目标吗？

节点:

XmlNode xmlNodoCE = docWebConfig.DocumentElement.SelectSingleNode("system.web/customErrors");

Answer 1

你需要

• 将文件加载到XmlDocument中,
• 检索要评论的节点,
• 创建一个包含原始节点的XML内容的注释节点,
• 将此注释添加到原始节点之前的原始父节点
• 从父母那里删除它,

• 将XmlDocument写入文件(同一个文件).

  String xmlFileName = "Sample.xml";
  
  // Find the proper path to the XML file
  String xmlFilePath = this.Server.MapPath(xmlFileName);
  
  // Create an XmlDocument
  System.Xml.XmlDocument xmlDocument = new System.Xml.XmlDocument();
  
  // Load the XML file in to the document
  xmlDocument.Load(xmlFilePath);
  
  // Get the target node using XPath
  System.Xml.XmlNode elementToComment = xmlDocument.SelectSingleNode("/configuration/system.web/customErrors");
  
  // Get the XML content of the target node
  String commentContents = elementToComment.OuterXml;
  
  // Create a new comment node
  // Its contents are the XML content of target node
  System.Xml.XmlComment commentNode = xmlDocument.CreateComment(commentContents);
  
  // Get a reference to the parent of the target node
  System.Xml.XmlNode parentNode = elementToComment.ParentNode;
  
  // Replace the target node with the comment
  parentNode.ReplaceChild(commentNode, elementToComment);
  
  xmlDocument.Save(xmlFilePath);