How to read the WSDL of a WCF service from a URL in C#

Question

I'm trying to read a WSDL from a URL to dynamically generate the proxy for the WCF service. This is my code:

XmlTextReader xmlTextReader = new XmlTextReader(new StringReader(description)) 
if (ServiceDescription.CanRead(xmlTextReader))
{
    ...
}

I get an XmlException from method ServiceDescription.CanRead.
The error massage is "Data at the root level is invalid. Line 1, position 1".

Browsing the WDSL URL in IE, I can see the following tag at the start before tag <wsdl:definitions ...> ... </wsdl:definitions> which doesn't appear in chrome.

<?xml version="1.0" encoding="UTF-8"?>

Could that be the issue? but I suppose ServiceDescription.CanRead should be able to recognise that. Any hints would be appreciated.

What about inspecting the XML that's being read? `CanRead` is just calling `CanDeserialize` on an inner instance of XmlSerializer and returning that value. — Scott Hannen, May 04 '17 at 02:06
And the xml declaration you're seeing in IE is optional but valid. [http://stackoverflow.com/questions/7007427/does-a-valid-xml-file-require-an-xml-declaration](http://stackoverflow.com/questions/7007427/does-a-valid-xml-file-require-an-xml-declaration) — Scott Hannen, May 04 '17 at 02:09
This could be it - an extra hidden character that prevents parsing of the XML. [http://stackoverflow.com/questions/17947238/why-data-at-the-root-level-is-invalid-line-1-position-1-for-xml-document/24513288](http://stackoverflow.com/questions/17947238/why-data-at-the-root-level-is-invalid-line-1-position-1-for-xml-document/24513288) — Scott Hannen, May 04 '17 at 02:11
Try pasting the code from my answer above the first line of code in your post. I don't know if it's the fix in this case but maybe it's worth a shot. — Scott Hannen, May 04 '17 at 02:36

score 1 · Accepted Answer · edited May 23 '17 at 11:33

1

Try adding this before the first line included in your question:

var byteOrderMarkUtf8 = Encoding.UTF8.GetString(Encoding.UTF8.GetPreamble());
if (description.StartsWith(byteOrderMarkUtf8))
{
    var lastIndexOfUtf8 = byteOrderMarkUtf8.Length - 1;
    description = description.Remove(0, lastIndexOfUtf8);
}

Borrowed from here.

edited May 23 '17 at 11:33

Community

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answered May 04 '17 at 02:15

Scott Hannen

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I initially deleted this because it's mostly copy and paste from someone else's answer to another question with trivial edits. I'm going to delete it again after OP gets a chance to try it. – Scott Hannen May 04 '17 at 02:37
Thanks Scott, that was the issue. fixed now! – Hamid Heydarian May 04 '17 at 02:57

How to read the WSDL of a WCF service from a URL in C#

1 Answers1