Read X-Forwarded-For header

I want to read the value of the X-Forwarded-For header value in a request.

I've tried

HttpContext.Current.Request.Headers["X-Forwarded-For"].Split(new char[] { ',' }).FirstOrDefault();  

in C#.

OR do I need to split the header by ":" and the take the second string? I am asking this because, Wikipedia says

The general format of the field is: X-Forwarded-For: client1, proxy1, proxy2