在XML文件VB.net中查找属性值

Question

我有以下详细信息包括xml文件。

<?xml version="1.0" encoding="utf-8"?>
<LoadSurveyValues>
  <LoadSurvey timeStamp="18/12/2015 11:13:02" saveMode="SnapShot">
    <Date Date="18/12/2015 00:00:00">
      <ParamValues Type="ActiveTotalImport" Unit="kWh">
        <SipValues Time="00:15" ParamValue="0" />
        <SipValues Time="00:30" ParamValue="0" />
        <SipValues Time="00:45" ParamValue="0" />
        <SipValues Time="01:00" ParamValue="0" />
        <SipValues Time="01:15" ParamValue="0.5" />
        <SipValues Time="01:30" ParamValue="0.1" />
        <SipValues Time="01:45" ParamValue="0" />
        <SipValues Time="02:00" ParamValue="0" />
        <SipValues Time="02:15" ParamValue="0" />
        <SipValues Time="02:30" ParamValue="0" />

等等

我想在“日期”日期18/12/2015，“ ParamValues”类型ActiveTotalImport”和“ SipValue”时间01:15中找出“ ParamValue”属性值，结果应为0.5。

这些是我在VB.net中使用列表框尝试过的代码。

  Dim xr As XmlReader = XmlReader.Create("meter 01.xml")
  If ListBox1.SelectedIndex >= 0 Then
        If ListBox2.SelectedIndex >= 0 Then
            If ListBox3.SelectedIndex >= 0 Then

                If xr.NodeType = XmlNodeType.Element And xr = ListBox1.SelectedIndex And xr = ListBox2.SelectedIndex And xr = ListBox3.SelectedIndex Then

                    ListBox4.Items.Add(xr.GetAttribute(1))

                End If
            End If
        End If
    End If

ListBox1选择了18/12/2015 00:00:00值，ListBox2选择了ActiveTotalImport值，ListBox3选择了01:15值。 因此，结果将添加到值为0.5的ListBox4中。 但是此代码不起作用，请帮我解决

Answer 1

试试xml linq

Imports System.Xml
Imports System.Xml.Linq
Module Module1
    Const FILENAME As String = "c:\temp\test.xml"
    Sub Main()
        Dim doc As XDocument = XDocument.Load(FILENAME)

        Dim survey As XElement = doc.Descendants("LoadSurvey").Where(Function(x) x.Attribute("timeStamp").Value = "18/12/2015 11:13:02").FirstOrDefault()
        Dim ParamValue As String = survey.Descendants("SipValues").Where(Function(x) x.Attribute("Time").Value = "01:15").Select(Function(y) y.Attribute("ParamValue")).FirstOrDefault()
    End Sub

End Module