尝试读取XML文档时，节点返回null

Question

i've programmically written an xml document to store some data and when i try to load it back into my application in a different area all of my Xmlnodes are returning null even though the node name i've given it is identical. This is preventing me from extracting the innertext of each node.

Question: What am i missing that is preventing me from reading this xml document

Code:

var xmlDocument = new XmlDocument();
xmlDocument.Load(@"\\mi\dfs\shared\Everyone\The Guy Technology\cavanaugh\OutageInformationDocument.xml");

XmlNode title = xmlDocument.SelectSingleNode("TitleTextvariable");
XmlNode type = xmlDocument.SelectSingleNode("TypeTextvaraible");
XmlNode information = xmlDocument.SelectSingleNode("InformationText");
XmlNode conference = xmlDocument.SelectSingleNode("ConferenceText");
XmlNode steps = xmlDocument.SelectSingleNode("StepsText");
XmlNode eta = xmlDocument.SelectSingleNode("EtaText");
XmlNode phone = xmlDocument.SelectSingleNode("PhoneMessageText");
XmlNode banner = xmlDocument.SelectSingleNode("BannerText");

XML Example:

<OutageInfo>
  <OutageInformation>
    <OutageInfoitems>
      <TitleTextvariable>title text</TitleTextvariable>
      <TypeTextvaraible>info</TypeTextvaraible>
      <InformationText>this is a test of the outage information</InformationText>
      <ConferenceText>information</ConferenceText>
      <StepsText>resolve it in this way</StepsText>
      <EtaText>30 minutes</EtaText>
      <PhoneMessageText>There is currently a phone message up</PhoneMessageText>
      <BannerText>There is not currently a banner posted</BannerText>
    </OutageInfoitems>
  </OutageInformation>
</OutageInfo>

Answer 1

You could use XElement :

var xml = XElement.Load(pathToFile);
var infoItem = xml.Descendants("OutageInfoitems").First();
var title = (string)infoItem.Element("TitleTextvariable");

The casting element to string (in the last line) is preferable way, because if there's no such element, then title will be null rather throwing exception .

Answer 2

The method you are using, XmlNode.SelectSingleNode(string xpath) , selects the first XmlNode that matches the XPath expression passed in as the argument value.

Thus you need to use the XPath recursive descent operator // to descend your XML node hierarchy to pick out deeply nested nodes:

XmlNode title = xmlDocument.SelectSingleNode("//TitleTextvariable");
XmlNode type = xmlDocument.SelectSingleNode("//TypeTextvaraible");
XmlNode information = xmlDocument.SelectSingleNode("//InformationText");
XmlNode conference = xmlDocument.SelectSingleNode("//ConferenceText");
XmlNode steps = xmlDocument.SelectSingleNode("//StepsText");
XmlNode eta = xmlDocument.SelectSingleNode("//EtaText");
XmlNode phone = xmlDocument.SelectSingleNode("//PhoneMessageText");
XmlNode banner = xmlDocument.SelectSingleNode("//BannerText");      

For more see Context for XPath Expressions :

The evaluation of an XPath expression depends on the context against which the expression operates. The context consists of the node against which the expression is evaluated and its associated environment, which includes the following...

Recursive descent

An expression that uses the double forward slash (//) indicates a search that can include zero or more levels of hierarchy. When this operator appears at the beginning of the pattern, the context is relative to the root of the document.

Working .Net fiddle .