XDocument isn't returning any values

Question

I'm reading in some XML from a file. In the file, the XML is stored as one single line of text, like this:

<ArrayOfKeyValueOfstringanyType xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays"><KeyValueOfstringanyType><Key>askforreview</Key><Value xmlns:d3p1="http://www.w3.org/2001/XMLSchema" i:type="d3p1:boolean">false</Value></KeyValueOfstringanyType><KeyValueOfstringanyType><Key>started</Key><Value xmlns:d3p1="http://www.w3.org/2001/XMLSchema" i:type="d3p1:int">1</Value></KeyValueOfstringanyType><KeyValueOfstringanyType><Key>LastRunVersion</Key><Value xmlns:d3p1="http://www.w3.org/2001/XMLSchema" i:type="d3p1:int">148</Value></KeyValueOfstringanyType> ... etc

I'm reading the file in with a StreamReader, calling XDocument.Load. With the code in debugging, if I dump the variable that is the XDocument, Visual Studio prints out the XML in a formatted manner, suggesting that XDocument has properly parsed the single line of text:

<ArrayOfKeyValueOfstringanyType xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
  <KeyValueOfstringanyType>
    <Key>askforreview</Key>
    <Value xmlns:d3p1="http://www.w3.org/2001/XMLSchema" i:type="d3p1:boolean">false</Value>
  </KeyValueOfstringanyType>
  <KeyValueOfstringanyType>
    <Key>started</Key>
    <Value xmlns:d3p1="http://www.w3.org/2001/XMLSchema" i:type="d3p1:int">1</Value>
  </KeyValueOfstringanyType>
  <KeyValueOfstringanyType>
    <Key>LastRunVersion</Key>
    <Value xmlns:d3p1="http://www.w3.org/2001/XMLSchema" i:type="d3p1:int">148</Value>
  </KeyValueOfstringanyType>

etc

However, attempts to pull out elements, descendants, values, etc pretty much all result in null being returned. My concern is that if I call .Root, I again get all of the XML displayed, along with this:

FirstAttribute: {xmlns:i="http://www.w3.org/2001/XMLSchema-instance"}
HasAttributes: true
HasElements: true
IsEmpty: false
LastAttribute: {xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays"}
Name: {{http://schemas.microsoft.com/2003/10/Serialization/Arrays}ArrayOfKeyValueOfstringanyType}
NodeType: Element
Value: "askforreviewfalsestarted1LastRunVersion148 ... etc"

In other words, it looks like all of the values have been run together?

Update: clarity of what I've been trying to do ...

Given the suggestion about namespaces, I've tried this:

oldSettings = XDocument.Load(sr);
XNamespace f ="http://schemas.microsoft.com/2003/10/Serialization/Arrays";
XElement f1 = oldSettings.Element(f + "KeyValueOfstringanyType");

(Please excuse the var names - this is just in the Immediate Window)

That returns f1 as null. If I try:

f1 = oldSettings.Element(f + "ArrayOfKeyValueOfstringanyType");

then f1 is set to the whole of the XML document since that is the root element. Calling f1.Descendants() gives me nothing again.

Am I referencing the correct namespace? ArrayOfKeyValueOfstringanyType seems to have two - the one I've used above, plus the one that starts 'xmlns:i="https://...'.

If I try:

var f2 = oldSettings.Elements(f + "KeyValueOfstringanyType");

or

var f2 = oldSettings.Descendants(f + "KeyValueOfstringanyType");

or

var f2 = oldSettings.Root.Descendants(f + "KeyValueOfstringanyType");

I get null.

Following the example given in http://msdn.microsoft.com/en-us/library/bb669152.aspx, I've also tried this:

XNamespace xns = "http://schemas.microsoft.com/2003/10/Serialization/Arrays";
IEnumerable<XElement> kv = from el in oldSettings.Elements(xns + "KeyValueOfstringanyType")
                           select el;
var f4 = kv.ToList();

and f4 is also null.

What do I need to do in order to get this working? Do I need to reformat the XML to introduce new line characters? (The file isn't being created by me)

Thanks.

You have not provided any code so it is hard to give any advice. However, does your code take namespaces into account? http://stackoverflow.com/questions/2998710/xdocument-containing-namespaces — Martin Liversage, Aug 05 '14 at 07:14
Thanks, Martin. Having read that linked SO Q&A, I've now updated my question with more detail. — Philip Colmer, Aug 05 '14 at 07:47

score 1 · Accepted Answer · edited May 23 '17 at 12:29

Looking at those codes you've tried, seems that you're just unlucky :p The element you're trying to access is direct child of root element, so this one will get the desired element :

XElement f1 = oldSettings.Root.Element(f + "KeyValueOfstringanyType");

In case of using Descendant you need to call ToList() or ToArray(), or iterate through the result to see the actual content :

var f2 = oldSettings.Descendants(f + "KeyValueOfstringanyType").ToList();

Question similar to your problem when using Descendants() : C# XML Node Works with Element But Not with Elelments

score 1 · Answer 2 · answered Aug 05 '14 at 08:08

You are simply making some simple mistakes:

XElement f1 = oldSettings.Element(f + "KeyValueOfstringanyType");

should be changed into

XElement f1 = oldSettings.Root.Element(f + "KeyValueOfstringanyType");

because you are looking for elements below the root element.

var f2 = oldSettings.Descendants(f + "KeyValueOfstringanyType");

will return the expected elements and not null so surely you must have som spelling mistake somewhere in your code.

XDocument isn't returning any values

2 Answers2