Question

How can I remove invalid xml comments that contain double dashes(--) from an xml file?

I’m trying to load the xml file, but it is failing. These comments make the xml invalid. The xml comes from a vendor.

I tried removing these based on approaches from other posts, but I was not successful. Here is an example of the xml:

<?xml version="1.0" encoding="ISO-8859-1"?>
<!--MAIN VARIABLES-->
<content type="screwed">
<!--KEEP 19-39 -- SEE HELP.TXT AND THE VIDEO TUTORIALS FOR MORE INFO -->
<!--REGULAR/NON-Regular EXAMPLE --><SomeTag somefile="test.txt3" Name="test"/>
<!-- -->
</content>

I have tried the following without success:

string xmlDocFile = "c:\server\test.xml";

XmlReaderSettings readerSettings = new XmlReaderSettings();
readerSettings.IgnoreComments = true;
readerSettings.ProhibitDtd = false;
readerSettings.ValidationType = ValidationType.DTD;
XmlReader reader = XmlReader.Create(xmlDocFile, readerSettings);
XmlDocument myXmlDoc = new XmlDocument();
myXmlDoc.Load(reader);
myXmlDoc.Save(xmlDocFile);

Answer 1

Before using XmlReader, parse xml file and filter comments using regexp.

// using System.Text.RegularExpressions;
System.IO.StreamReader file= new System.IO.StreamReader(xmlDocFile);
string validXml = Regex.Replace(file.ReadToEnd(),"<!--.*?-->","");

XmlReader reader = XmlReader.Create(validXml);