The System.IO.Directory class exposes a CreateDirectory method that, as its name suggests, can create a subdirectory. However, this method is even more powerful than it appears at a first glance, in that it can even create all
the intermediate subdirectories, if necessary. In other words, the following statement:
creates both the C:\MyApp and the C:\MyApp\MySubDir directories, if they don't exist already, before creating the Data folder.