Currently I am using the solution provided by Carlos Quintero (MZTools] to iterate through the Solution Herarchy. Here is the link:
http://www.mztools.com/articles/2014/MZ2014010.aspx
This solution works fine but for a solution with a large number of files (Roslyn project for example) it takes too long.
Is there another way to iterate a Solution hierarchy and get ICONs for all files/folders in that solution using Roslyn?