Question

在这里遇到一个小问题，我正在为客户开发一个传统的经典ASP应用程序，并且需要从XML文件中提取数据但是我无法获得单个节点的值，我的代码只返回任何内容。 / p>

我已经能够从XML文件中提取所有数据而没有任何问题。

XML文件

<?xml version="1.0" encoding="UTF-8"?>
<Devices-Detail-Response>
   <PollCount>36593</PollCount>
   <DevicesConnected>1</DevicesConnected>
   <LoopTime>1.031</LoopTime>
   <DataErrors>0</DataErrors>
   <DeviceName>OW_SERVER-Enet</DeviceName>
   <HostName>EDSOWSERVER</HostName>
   <MACAddress>00:50:C2:91:B3:9C</MACAddress>
   <owd_DS18B20 Description="Programmable resolution thermometer">
      <Name>DS18B20</Name>
      <Family>28</Family>
      <ROMId>2D0000023C519A28</ROMId>
      <Health>7</Health>
      <RawData>61014B467FFF0F1002FF000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000</RawData>
      <PrimaryValue>22.0625 Deg C</PrimaryValue>
      <Temperature Units="Centigrade">22.0625</Temperature>
      <UserByte1 Writable="True">75</UserByte1>
      <UserByte2 Writable="True">70</UserByte2>
      <Resolution>12</Resolution>
      <PowerSource>255</PowerSource>
   </owd_DS18B20>
</Devices-Detail-Response>

xml-text.asp文件

<%
Option Explicit 
Response.Write GetTemperature("http://192.168.1.85/details.xml", "2D0000023C519A28")
Function GetTemperature(strXMLFile, strName)

Dim objXML : Set objXML = CreateObject("Msxml2.DOMDocument.6.0")
objXML.async = False
objXML.SetProperty "SelectionLanguage", "XPath"
objXML.SetProperty "ServerHTTPRequest", True
objXML.load(strXMLFile)

''// enclose in single- or double quotes accordingly
If InStr(strName, "'") > 0 And InStr(strName, """") = 0 Then
    strName = """" & strName & """"
    ElseIf InStr(strName, "'") = 0 And InStr(strName, """") > 0 Then
        strName = "'" & strName & "'"
    Else
        ''// both single and double quotes in a string are unsupported
        strName = "''"  
End If

Dim strXPath : strXPath = "/Devices-Detail-Response/owd_DS18B20[ROMId=" & strName & "]/Temperature"
Dim objNode : Set objNode = objXML.documentElement.selectSingleNode(strXPath)

If Not objNode Is Nothing Then
    value = objNode.text
End If
End Function 
%>

value = objNode.text根本不返回任何内容，如果我沿着XPath返回，我仍然什么也得不到。

已经很晚了，我知道我错过了一些简单的事情？！

干杯，

奥奇

更新：如果我执行以下操作，请在此处稍加更新：

Dim xmlSensor 
For Each xmlSensor In objXML.documentElement.selectNodes("owd_DS18B20") 
Dim romID : romID = xmlSensor.selectSingleNode("ROMId").text 
Dim temperature : temperature = xmlSensor.selectSingleNode("Temperature").text
Response.Write Server.HTMLEncode(romID) & "<br />"
Response.Write Server.HTMLEncode(temperature) & "<br /><br />"
Next

我得到了所需的值，问题是最多可以链接24个传感器，ROMId是唯一的标识符，所以我们真的需要对此进行过滤，所以问题必须与我认为的XPATH字符串有关。

Answer 1

我认为您在替换块中缺少ElseIf条件。

If InStr(strName, "'") > 0 And InStr(strName, """") = 0 Then
        strName = """" & strName & """"
    ElseIf InStr(strName, "'") = 0 And InStr(strName, """") > 0 Then
        strName = "'" & strName & "'"
    ElseIf InStr(strName, "'") > 0 And  InStr(strName, """") > 0 Then
        ''// both single and double quotes in a string are unsupported
        strName = "''"  
End If

Answer 2

鉴于@SearchAndResQ给出的指针，我修改了函数，如下所示：

Function GetTemperature(strXMLFile, strName)

Dim value
Dim objXML : Set objXML = CreateObject("MSXML2.DOMDocument.3.0")
objXML.async = False
objXML.load(strXMLFile)

Dim strXPath : strXPath = "/Devices-Detail-Response/owd_DS18B20[ROMId='" & strName & "']"
Dim xmlSensor       
For Each xmlSensor In objXML.documentElement.selectNodes(strXPath)
     Dim romID : romID = xmlSensor.selectSingleNode("ROMId").text   
     Dim temperature : temperature = xmlSensor.selectSingleNode("Temperature").text   
     Response.Write Server.HTMLEncode(romID) & "<br />"
     Response.Write Server.HTMLEncode(temperature) & "<br /><br />"   
Next      
End Function

请注意，我已删除了字符串替换部分，并将单引号硬编码为XPath字符串。

现在，即使连接了多个传感器，也可以提供所需的数据。 :-)谢谢大家

XPath没有返回节点值

2 个答案: