关于StdAfx.h和StdAfx.cpp

http://www.cplusplus.com/articles/2z86b7Xj/

https://msdn.microsoft.com/en-us/library/h552b3ca.aspx

https://en.wikipedia.org/wiki/Precompiled_header

http://stackoverflow.com/questions/676385/stdafx-h-when-do-i-need-it#