Descendants<T> gets zero elements in Word doc

问题

I am having trouble updating a Hyperlink in a Word doc (Q How to update the body and a hyperlink in a Word doc ) and am zooming in on the Descendants<T>() call not working. Here is my code:

using DocumentFormat.OpenXml.Packaging;      //from NuGet ClosedXML
using DocumentFormat.OpenXml.Wordprocessing; //from NuGet ClosedXML

WordprocessingDocument doc = WordprocessingDocument.Open(...filename..., true);
MainDocumentPart mainPart = doc.MainDocumentPart;
IEnumerable<Hyperlink> hLinks = mainPart.Document.Body.Descendants<Hyperlink>();

The doc is opened OK because mainPart gets a value. But hLinks has no elements. If I open the Word doc in Word, a hyperlink is present and working.

In the Immediate Window I see the following values:

mainPart.Document.Body
-->
{DocumentFormat.OpenXml.Wordprocessing.Body}
    ChildElements: {DocumentFormat.OpenXml.OpenXmlChildElements}
    ExtendedAttributes: {DocumentFormat.OpenXml.EmptyEnumerable<DocumentFormat.OpenXml.OpenXmlAttribute>}
    FirstChild: {DocumentFormat.OpenXml.OpenXmlUnknownElement}
    HasAttributes: false
    HasChildren: true
    InnerText: "
       lots of data, e.g:
    ...<w:t>100</w:t>...

mainPart.Document.Body.Descendants<Text>().First()
-->
Exception: "Sequence contains no elements"

If I cannot even find the text parts, how should I ever find and replace the hyperlink?

回答1:

If you are sure there are elements in your file that you are searching with linq, and nothing is returning or you are getting exceptions, that typically points to a namespace problem.

If you post your entire file, I can better help you, but check to see if you can alias your namespace like so:

using W = DocumentFormat.OpenXml.Wordprocessing;

and then in your Descendants call you do something like this:

var hLinks = mainPart.Document.Body.Descendants<W.Hyperlink>();

This answer demonstrates another namespace trick to try also.

回答2:

Something seems to be wrong with my Word doc; it was generated with a tool. Testing with another Word doc, created with Word, gives better results. I am working on it ...

With a regular Word doc, looking at

doc.MainDocumentPart.Document.Body.InnerXml

the value starts with:

<w:p w:rsidR=\"00455325\" w:rsidRDefault=\"00341915\" 
  xmlns:w=\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\">
  <w:r>
    <w:t>Hello World!

but with the word doc I am testing with, which comes from a tool I myself made:

<w:body xmlns:w=\"http://schemas.openxmlforma...

This explains a lot. I will have to fix my tool :-)

---

Update:

The fix was that this did not give the correct part of data to insert in the Word Doc:

string strDocumentXml = newWordContent.DocumentElement.InnerXml;

but instead this is the correct data:

string strDocumentXml = newWordContent.DocumentElement.FirstChild.OuterXml;

Inspection with the debugger of:

doc.MainDocumentPart.Document.Body.InnerXml

as mentioned above, confirmed it. The Descendants call now returns the expected data, and updating the hyperlink works.

---

Side note:

I clearly fixed a bug in my app, but, apart from updating the hyperlink, the app worked perfectly OK before, with that bug :-)

来源：https://stackoverflow.com/questions/54331068/descendantst-gets-zero-elements-in-word-doc