using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"<!--(?!\s*(?:\[if [^\]]+]|<!|>))(?:(?!-->)(.|\n))*-->";
string input = @"<!-- some comments 1 -->
<!-- 1.91 -->
<!--
//-->
<!-- -->
<!--[if IE]> <![endif]-->
<!--[if !IE]><!--> <!--<![endif]-->
<!--[if IE 6]> <![endif]-->";
RegexOptions options = RegexOptions.Multiline | RegexOptions.Singleline;
Match m = Regex.Match(input, pattern, options);
Console.WriteLine("'{0}' found at index {1}", m.Value, m.Index);
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx