c# - 读取多个 XML 属性

Question

我正在尝试在 Visual Studio 中使用 C# 从 XML 库(下面的文件)获取信息。

<buttons>
<measurement>
    <scan id="0" time="20 53 06">
        <q address="40" state="0"/>
        <q address="41" state="0"/>
        <q address="42" state="1"/>
        <q address="43" state="0"/>
        <q address="44" state="1"/>
        <q address="45" state="1"/>
        <q address="46" state="1"/>
        <q address="47" state="1"/>
    </scan>
</measurement>
<measurement>
    <scan id="1" time="20 53 07">
        <q address="40" state="0"/>
        <q address="41" state="0"/>
        <q address="42" state="0"/>
        <q address="43" state="0"/>
        <q address="44" state="1"/>
        <q address="45" state="0"/>
        <q address="46" state="0"/>
        <q address="47" state="0"/>
    </scan>
</measurement>
<measurement>
    <scan id="2" time="20 53 08">
        <q address="40" state="0"/>
        <q address="41" state="1"/>
        <q address="42" state="0"/>
        <q address="43" state="1"/>
        <q address="44" state="1"/>
        <q address="45" state="0"/>
        <q address="46" state="0"/>
        <q address="47" state="1"/>
    </scan>
</measurement>
<measurement>
    <scan id="3" time="20 53 09">
        <q address="40" state="1"/>
        <q address="41" state="0"/>
        <q address="42" state="0"/>
        <q address="43" state="1"/>
        <q address="44" state="1"/>
        <q address="45" state="0"/>
        <q address="46" state="1"/>
        <q address="47" state="0"/>
    </scan>
</measurement>
<measurement>
    <scan id="4" time="20 53 10">
        <q address="40" state="0"/>
        <q address="41" state="0"/>
        <q address="42" state="1"/>
        <q address="43" state="1"/>
        <q address="44" state="1"/>
        <q address="45" state="1"/>
        <q address="46" state="0"/>
        <q address="47" state="0"/>
    </scan>
</measurement>
<measurement>
    <scan id="5" time="20 53 11">
        <q address="40" state="1"/>
        <q address="41" state="1"/>
        <q address="42" state="1"/>
        <q address="43" state="0"/>
        <q address="44" state="0"/>
        <q address="45" state="0"/>
        <q address="46" state="1"/>
        <q address="47" state="0"/>
    </scan>
</measurement>
<measurement>
    <scan id="6" time="20 53 12">
        <q address="40" state="0"/>
        <q address="41" state="1"/>
        <q address="42" state="1"/>
        <q address="43" state="0"/>
        <q address="44" state="0"/>
        <q address="45" state="1"/>
        <q address="46" state="1"/>
        <q address="47" state="1"/>
    </scan>
</measurement>
<measurement>
    <scan id="7" time="20 53 13">
        <q address="40" state="1"/>
        <q address="41" state="1"/>
        <q address="42" state="1"/>
        <q address="43" state="1"/>
        <q address="44" state="1"/>
        <q address="45" state="0"/>
        <q address="46" state="1"/>
        <q address="47" state="1"/>
    </scan>
</measurement>

这是我第一次尝试读取 xml 文件。

这就是我想做的:
我想输入 ID，程序应该返回数组中的所有 q 状态。

这是我尝试过的:

using System.Xml;
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load("Path to my xml");
XmlNodeList titleNodes = xmlDoc.SelectNodes("//buttons/measurment/scan/q");
foreach(XmlNode titleNode in titleNodes)
    Console.WriteLine(titleNode.Attribute["address"]);
Console.ReadKey();

我知道这段代码只会在控制台中显示一些 q 属性。我从来没有走得更远，因为它不起作用(控制台窗口中没有出现任何内容)。我不知道为什么。我只是不明白这个XmlRead，XmlDeocument。我在这里学习:Tutorial 。我关注着每一个词干和例子。只有 XmlRead 给了我一些东西。但它只读取所有内容，而不读取特定区域。

您能给我一些示例或解决方案吗？

Answer 1

考虑使用 XDocument，它允许您使用 LINQ，使您的 xml 生活更轻松:

string myId = "2";

var doc = XDocument.Parse(xmlString); //or XDocument.Load(filePath)

//find the correct 'scan' node based on your id
var scan = doc.Descendants("scan")
              .FirstOrDefault(s => s.Attribute("id").Value == myId);

//grab all q's and get their 'state' for that 'scan' node
var states = scan?.Descendants("q")
                  .Select(q => q.Attribute("state").Value);

foreach (var state in states)
{
    Console.WriteLine(state);
}