如何使用 LINQ 到 XML 生成顺序属性值

Question

我有一些格式如下或略有不同的 xml 文件

<?xml version="1.0"?>
<!DOCTYPE PARTS SYSTEM "parts.dtd">
<?xml-stylesheet type="text/css" href="xmlpartsstyle.css"?>
<PARTS>
    <TITLE>Computer Parts</TITLE>
    <ASST>
        <PART no="xs@@">
            <ITEM>Motherboard</ITEM>
            <MANUFACTURER>ASUS</MANUFACTURER>
            <MODEL ver="v-@@@@">P3B-F</MODEL>
            <COST>123.00</COST>
        </PART>
        <PART no="xs@@">
            <ITEM>Video Card</ITEM>
            <MANUFACTURER>ATI</MANUFACTURER>
            <MODEL ver="v-@@@@">All-in-Wonder Pro</MODEL>
            <COST>160.00</COST>
        </PART>
        <PART no="xs@@">
            <ITEM>Sound Card</ITEM>
            <MANUFACTURER>Creative Labs</MANUFACTURER>
            <MODEL ver="v-@@@@">Sound Blaster Live</MODEL>
            <COST>80.00</COST>
        </PART>
    </ASST>
</PARTS>

我正在尝试以顺序方式生成节点 <PART> 的属性值，即 no 和 <MODEL> 即 ver，从值 1 开始，然后从下一个<PART>节点递增 +1。所以，基本上所需的输出应该看起来像这样

<?xml version="1.0"?>
<!DOCTYPE PARTS SYSTEM "parts.dtd">
<?xml-stylesheet type="text/css" href="xmlpartsstyle.css"?>
<PARTS>
    <TITLE>Computer Parts</TITLE>
    <ASST>
        <PART no="xs1">
            <ITEM>Motherboard</ITEM>
            <MANUFACTURER>ASUS</MANUFACTURER>
            <MODEL ver="v-1">P3B-F</MODEL>
            <COST>123.00</COST>
        </PART>
        <PART no="xs2">
            <ITEM>Video Card</ITEM>
            <MANUFACTURER>ATI</MANUFACTURER>
            <MODEL ver="v-2">All-in-Wonder Pro</MODEL>
            <COST>160.00</COST>
        </PART>
        <PART no="xs3">
            <ITEM>Sound Card</ITEM>
            <MANUFACTURER>Creative Labs</MANUFACTURER>
            <MODEL ver="v-3">Sound Blaster Live</MODEL>
            <COST>80.00</COST>
        </PART>
    </ASST>
</PARTS>

那么，使用 LINQ to-XML 执行此操作的最简单方法是什么？

我试图像

string filecontent=File.ReadAllText(@"C:UsersDesktop12-apr.xml");
XDocument xml=XDocument.Parse(filecontent);
var parts=xml.Descendants("PART");
var models=xml.Descendants("PART").Elements("MODEL");
foreach (var part in parts)
{
    for (int i = 0; i < parts.Count(); i++)
    {
        part.Attribute("no").Value="xs"+i.ToString();
    }
}
foreach (var model in models)
{
    for (int i = 0; i < parts.Count(); i++)
    {
        model.Attribute("ver").Value="v-"+i.ToString();
    }
}
xml.Save(@"C:UsersDesktop12-apr.xml");
Console.ReadLine();

但它没有按照我想要的方式工作。我的代码生成的输出

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE PARTS SYSTEM "parts.dtd"[]>
<?xml-stylesheet type="text/css" href="xmlpartsstyle.css"?>
<PARTS>
  <TITLE>Computer Parts</TITLE>
  <ASST>
    <PART no="xs2">
      <ITEM>Motherboard</ITEM>
      <MANUFACTURER>ASUS</MANUFACTURER>
      <MODEL ver="v-2">P3B-F</MODEL>
      <COST>123.00</COST>
    </PART>
    <PART no="xs2">
      <ITEM>Video Card</ITEM>
      <MANUFACTURER>ATI</MANUFACTURER>
      <MODEL ver="v-2">All-in-Wonder Pro</MODEL>
      <COST>160.00</COST>
    </PART>
    <PART no="xs2">
      <ITEM>Sound Card</ITEM>
      <MANUFACTURER>Creative Labs</MANUFACTURER>
      <MODEL ver="v-2">Sound Blaster Live</MODEL>
      <COST>80.00</COST>
    </PART>
  </ASST>
</PARTS>

帮助

Answer 1

你无缘无故地嵌套了循环......您为每个元素多次设置属性，而不是为每个元素设置一次属性。

一旦你摆脱了嵌套循环，它就很简单了。不过，如果您将查询具体化为列表，则更简单。下面是生成所需输出的完整示例：

using System;
using System.Linq;
using System.Xml.Linq;
class Test
{
    static void Main()
    {
        var xml = XDocument.Load("input.xml");
        var parts = xml.Descendants("PART").ToList();
        var models = xml.Descendants("PART").Elements("MODEL").ToList();
        for (int i = 0; i < parts.Count; i++)
        {
            parts[i].Attribute("no").Value = $"xs{i+1}";
        }
        for (int i = 0; i < models.Count; i++)
        {
            models[i].Attribute("ver").Value = $"v-{i+1}";
        }
        xml.Save("output.xml");
    }
}