将 SelectSingleNode 与 XPath 一起使用返回 NULL [英] Using SelectSingleNode with XPath returns NULL

问题描述

我尝试使用 SelectSingleNode 修改 XML 文件.文件结构为

I trying to modify an XML file with SelectSingleNode. The structure of file is

<?xml version="1.0" encoding="utf-8"?>
<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<ProjectExtensions>
    <Borland.Personality>Delphi.Personality</Borland.Personality>
    <Borland.ProjectType>VCLApplication</Borland.ProjectType>
    <BorlandProject>
      <BorlandProject>
        <Delphi.Personality>
          <Parameters>
            ...
          </Parameters>
          <VersionInfo>
            <VersionInfo Name="IncludeVerInfo">True</VersionInfo>
            <VersionInfo Name="AutoIncBuild">False</VersionInfo>
            <VersionInfo Name="MajorVer">4</VersionInfo>
            <VersionInfo Name="MinorVer">1</VersionInfo>
            <VersionInfo Name="Release">3</VersionInfo>
            <VersionInfo Name="Build">559</VersionInfo>
            <VersionInfo Name="Debug">False</VersionInfo>
            <VersionInfo Name="PreRelease">False</VersionInfo>
            <VersionInfo Name="Special">False</VersionInfo>
            <VersionInfo Name="Private">False</VersionInfo>
            <VersionInfo Name="DLL">False</VersionInfo>
            <VersionInfo Name="Locale">1049</VersionInfo>
            <VersionInfo Name="CodePage">1251</VersionInfo>
          </VersionInfo>
...
...
...

我在 VS C# 上的代码是

My code on VS C# is

using System.Xml;

namespace xmledit
{
    class Program
    {
        private static void Main(string[] args)
        {
            XmlDocument doc = new XmlDocument();
            doc.Load("arm.xml");
            var node = doc.SelectSingleNode("//VersionInfo[@Name='Build']");
            if (node != null)
                node.InnerText = "123";                
            doc.Save("temp.xml");
        }
    }
}

所以，我试图用 Name="Build" 修改标签 VersionInfo，但 SelectSingleNode 返回 NULL.我做错了什么?

So, i trying to modify Tag VersionInfo with Name="Build", but SelectSingleNode returns NULL. What I doing wrong?

推荐答案

你的 xml 文档有一个默认的命名空间 xmlns="http://schemas.microsoft.com/developer/msbuild/2003"因此(我假设)您需要使用 XmlNamespaceManager.

Your xml document has an default namespace xmlns="http://schemas.microsoft.com/developer/msbuild/2003" therefore (I assume) you need to use a XmlNamespaceManager.

• http://msdn.microsoft.com/en-us/library/h0hw012b.aspx
• http://msdn.microsoft.com/en-us/library/d6730bwt.aspx

这篇关于将 SelectSingleNode 与 XPath 一起使用返回 NULL的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！