将XPathDocument转换为字符串

using System;
using System.IO;
using System.Xml;
using System.Xml.XPath;

public class XPathDocumentToString
{
    public static string ConvertToString(XPathDocument document)
    {
        StringWriter stringWriter = new StringWriter();
        XmlWriterSettings settings = new XmlWriterSettings();
        settings.OmitXmlDeclaration = true; // 忽略XML声明
        settings.Indent = true; // 格式化输出
        XmlWriter writer = XmlWriter.Create(stringWriter, settings);
        
        XPathNavigator navigator = document.CreateNavigator();
        navigator.MoveToRoot(); // 移动到根节点
        
        writer.WriteNode(navigator, true); // 将节点写入XmlWriter
        
        writer.Flush();
        return stringWriter.ToString();
    }
}

XPathDocument document = new XPathDocument("path/to/xml/file.xml");
string xmlString = XPathDocumentToString.ConvertToString(document);
Console.WriteLine(xmlString);