Usually, we do not "explain" the code taken by our inquirers somewhere on the Web, because doing so means loosing a huge amount of time for nothing. There is too much trash out there, so why trying to explain it all. On this forum, one of out experts demonstrated that "explanation" of a single code line could take a whole article. Remember, we know nothing about your background and knowledge and don't know how detailed the "explanation" should be. In other words, the notion of explanation is not well-defined. Anyway, not well enough to start such explanation. You rather need some general instruction on learning programming and APIs you need.—SA
You are supposed to write your own code, and, if you are stuck, ask for help. This would be much more effective. If you really want to look how others write code, do it, but, to get explanation 1) ask the author of it, 2) find each and every word you don't understand and find it in the original documentation (in this case, MSDN). Actually, you need to do item #2 first, before asking any questions.
By the way, the code sample you show is almost self-explanatory. At the same time, in practice, reflecting the type by its name is a very bad technique, but this is only one line. Anyway, not understanding such code is rather a result of some laziness, which is normally a pretty good thing, but not in this case. You should not have looked at the sample code at all, before you read through the documentation. Only then reading someone else's code could be useful, to certain extent.