Question

Is it possible to use the .net Regex class to do a replace on a specific capture group.

for example

<customer.*?(display="(?:yes|no)")?.*?>

I want to match on the Customer xml element but replace within the display attribute capture group. i think that would be group 1, but i could always name this.

Answer 1

I think you’ll need to capture the stuff that comes before and after the display attribute.

(<customer.*?)(display="(?:yes|no)")(.*?>) 

You can then use that in your replace lambda

Regex.Replace(inputString, @"(<customer.*?)(display=""(?:yes|no)"")(.*?>)", m => String.Format("{0}{1}{2}", m.Groups[1], /* replacement string based on m.Groups[2] */, m.Groups[3]));