Question

I am working in replacing a text with a hyperlink in C#. The problem here is that the link has a question mark

Case 1:No problem

Input: ASAss123

Output:ASAss123

Case 2:Problem here

Input: ASAsq123

Output:ASAsq123“>ASAsq123

(Note: First occurrence of ASAss123 is hyperlink and is replaced as http://stack.com/temp/test?order=sam&identifier=<a href= and second occurrence is just plain text)

Preferred Output: ASAsq123

How can I rectify this problem. Code here for your reference:

 mailItem.HTMLBody = Regex.Replace(
     mailItem.HTMLBody,
     "(?<!http://stack.com/temp/test?order=sam&identifier=)ASA[a-z][a-z][0-9][0-9][0-9](?!</a>)",
     "<a href=\"http://stack.com/temp/test?order=sam&identifier=$&\">$&</a>");

The problem here is with the “?” found in the second argument. If I get rid this of “?” in both 2nd and 3rd arguments, this works perfectly fine.

But I cannot get rid of “?”, because it is needed for the URL to function. How can I solve this problem?

I tried escape sequence with \? and C sharp says escape sequence unrecognized…

Answer 1

You need to escape like this:

\\?

You are escaping ? In the regex, but \ needs to also be escaped in the c# string.