How can I access a single XML element's value

2019-03-29 19:40发布

问题:

I've looked at a lot of resources, done a lot of research, and tried many "best-guesses" to access a single element at a time using WebMatrix with C#, web-pages, however nothing I am trying is getting through.

Consider a simple xml document that looks like this:

<root>
    <requisitionData>
        <element1>I am element 1</element1>
        <element2>I am element 2</element2>
    </requisitionData>
</root>

I know I can use a foreach loop, like so:

@using System.Xml.Linq

XDocument doc = XDocument.Load(Server.MapPath("~/User_Saves/cradebaugh/testFile.xml"));

foreach (XElement element in doc.Descendants("requisitionData"))
{
    @element.Value
}

And that, of course, works fine. But what if I simply wanted to store the single element, <element1>'s value in a string variable?

I've looked here (link below), but I can't make heads or tails of this code (it barely even looks like C# to me, but then again, I'm so new to parsing XML...):

http://social.msdn.microsoft.com/Forums/en-US/csharpgeneral/thread/b14ce4d1-77f1-420d-ad91-0989794a1d45/

I've also checked here: How to Get XML Node from XDocument

But the code shown makes no sense to me here either. I keep thinking there must be a simpler way to do this, hopefully without learning a whole new querying approach.

---------------------------------THINGS I'VE TRIED---------------------------------

XDocument doc = XDocument.Load(Server.MapPath("~/User_Saves/cradebaugh/testFile.xml"));

string element = doc.Descendants("requisitionData").Descendants("element1").Value;

Error I receive: "missing using directive or assembly reference

XDocument doc = XDocument.Load(Server.MapPath("~/User_Saves/cradebaugh/testFile.xml"));

XElement element = doc.Descendants("element1");
string val = element.Value;

Error I receive: Cannot implicitly convert type 'System.Collections.Generic.IEnumerable' to 'System.Xml.Linq.XElement'. An explicit conversion exists (are you missing a cast?)

I have, indeed, tried other things, but I get pretty much the same errors as shown above. Am I making this harder than it is, or am I oversimplifying it?

-------------------------UPDATE------------------------------

I was able to get this to work:

string element = doc.Element("root").Element("requisitionData").Element("element1").Value;

@element

However, one thing that concerns me about this approach is that .Element selects the 'first' match, so in an xml document that looks like this:

<root>
    <requisitionData>
        <element1>I am element 1</element1>
        <element2>I am element 2</element2>
    </requisitionData>
    <requisitionData>
        <element1>I am element 1</element1>
        <element2>I am element 2</element2>
    </requisitionData>
</root>

How could I access the second occurrence of <element1>?

回答1:

@using System.Xml.Linq

XDocument doc = XDocument.Load(Server.MapPath("~/User_Saves/cradebaugh/testFile.xml"));

foreach (XElement element in doc.Element("root").Element("requisitionData").Descendants())
{
    string value = element.Value;
}

or with XPath:

@using System.Xml.Linq
@using System.Xml.XPath

XDocument doc = XDocument.Load(Server.MapPath("~/User_Saves/cradebaugh/testFile.xml"));

foreach (XElement element in doc.XPathSelectElement("//requisitionData").Descendants())
{
    string value = element.Value;
}

UPDATE:

And if you wanted to select for example the second <element1> node from your updated example:

string value = doc.XPathSelectElement("//requisitionData[2]/element1").Value;