如何匹配xml字符串末尾的斜线?

The Problem:
I want to match a certain xml substring (see below ex. A) using Regex. The problem is that I can’t match the slash at the end of xml string because its a meaningful char in Regex. I even tried to escape the slash by inserting a backslash before the slash in my pattern (see code below) but still couldn’t make it to work... I want to match a certain xml subs