xml - 在 Visual Basic 中解析 XML

Question

我很难弄清楚如何在 Visual Basic 中“正确”解析 XML 响应。我碰巧正在运行 Visual Studio 2013。我从我正在查询的 API 获得的响应看起来完全像这样(一些数据已更改以保护无辜者):

<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<person id="123456">
    <hos-status as-of="2015-05-20T18:53:39.592Z">
        <duty-status>ON</duty-status>
        <availability>
            <drive>22020000</drive>
            <shift>22020000</shift>
            <cycle>151320000</cycle>
        </availability>
        <rest-break>
            <max-drive>420000</max-drive>
            <rest-remaining>1800000</rest-remaining>
        </rest-break>
        <daily-log-summary date="2015-05-20">
            <duty-status code="OF">25200000</duty-status>
            <duty-status code="SL">0</duty-status>
            <duty-status code="DR">7800000</duty-status>
            <duty-status code="ON">20580000</duty-status>
        </daily-log-summary>
        <daily-log-summary date="2015-05-19">
            <duty-status code="OF">51600000</duty-status>
            <duty-status code="SL">0</duty-status>
            <duty-status code="DR">8580000</duty-status>
            <duty-status code="ON">26220000</duty-status>
        </daily-log-summary>
    </hos-status>
    <location as-of="2015-05-20T18:52:40.000Z">
        <position lat="12.345678" lon="-12.345678" accuracy="3"/>
        <speed>12</speed>
        <bearing>123.45</bearing>
    </location>
</person>

我可以解析它，但我这样做的方式肯定不直观。我花了几天时间阅读它，我所能找到的都是看起来和我正在做的一样丑陋的方法。显然，我遗漏了一些基本知识，我希望获得有关阅读内容的建议，以便我可以学习正确的方法。

这是我正在使用的代码/过程。首先，我调用 API 以通过以下函数获取响应:

Public Function getCurlXML(theURL As String) As Xml.XmlDocument
    getCurlXML = New Xml.XmlDocument
    Dim wHeader As WebHeaderCollection = New WebHeaderCollection()
    wHeader.Clear()
    Dim wRequest As HttpWebRequest = DirectCast(System.Net.HttpWebRequest.Create(theURL), HttpWebRequest)
    wRequest.ContentType = "text/xml"
    wRequest.Headers = wHeader
    wRequest.Method = "GET"
    Dim wResponse As HttpWebResponse = DirectCast(wRequest.GetResponse(), HttpWebResponse)
    Dim sResponse As String = ""
    Using srRead As New StreamReader(wResponse.GetResponseStream())
        sResponse = srRead.ReadToEnd()
    End Using
    getCurlXML.LoadXml(sResponse)
End Function

下面是我用来调用上述函数并进行解析的代码:

Public Function getThePersonStatus(personID As String) As Collection
    Dim statusColl As New Collection
    Dim sUrl As String = "https://api.THE.com/api/stuffage/" & personID & "/status?apiKey=" & My.Settings.TheAPIKey
    Dim doc As Xml.XmlDocument = getCurlXML(sUrl)
    Dim statusElemList As XmlNodeList = doc.GetElementsByTagName("hos-status")
    For Each thisNode As XmlNode In statusElemList
      If (thisNode.Name = "hos-status") Then
          statusColl.Add(thisNode.Attributes("as-of").Value.ToString, "hos-as-of")
          statusColl.Add(thisNode("duty-status").InnerText.ToString, "duty-status")
          Dim availElem As XmlNode = thisNode("availability")
          statusColl.Add(availElem("drive").InnerText.ToString, "drive")
          statusColl.Add(availElem("shift").InnerText.ToString, "shift")
          statusColl.Add(availElem("cycle").InnerText.ToString, "cycle")
      End If
    Next
    Dim locationElemList As XmlNodeList = doc.GetElementsByTagName("location")
    For Each thisNode As XmlNode In locationElemList
      statusColl.Add(thisNode.Attributes("as-of").Value.ToString, "loc-as-of")
      statusColl.Add(thisNode("speed").InnerText.ToString, "speed")
      statusColl.Add(thisNode("bearing").InnerText.ToString, "bearing")
      statusColl.Add(thisNode("position").Attributes("lat").Value.ToString, "lat")
      statusColl.Add(thisNode("position").Attributes("lon").Value.ToString, "lon")
      statusColl.Add(thisNode("position").Attributes("accuracy").Value.ToString, "gps-accuracy")
    Next
    getThePersonStatus = statusColl
End Function

基本上，我根据响应创建一个 XML 文档，然后搜索我感兴趣的元素，然后遍历该元素以查找我感兴趣的子节点。

有没有一种方法可以加载文档并引用类似于以下形式的特定元素:

doc.Elem("person").Elem("hos-status").Elem("availability").Elem("Shift").InnerText

我知道那里(或应该那里)有哪些元素，但无论我尝试什么，似乎都无法直接引用它们。

Answer 1

你应该能够使用这样的东西:

doc.DocumentElement.Item("hos-status").Item("availability").Item("shift").InnerText

但是，VB.NET 的优点之一是它使用 System.Xml.Linq 类(例如 XElement)对 XML 的 native 支持。 .这将允许你做这样的事情，对我来说它更具可读性(你需要弄清楚如何集成到你的代码中):

Dim xml = XElement.Load(wResponse.GetResponseStream())
Dim shift = x.<hos-status>.<availability>.<shift>.Value