The contact VC is already a big four time, and the truly starting to learn VC is 99 years, thanks to Hou Jie "in-depth MFC". It has been used for more than 1 year, I don't dare to say it, I have to master it. Yesterday, I opened the VC6 and started to study pure API programming, confusing a lot, and turned out "in-depth" and started the idea. Research API, the main purpose is to hide too much detail after Application Framework package, flexible and restricted - developers always want the programmer to fall into its own development model and weak. In fact, the API is the same, Microsoft's things, but it is better than being imprisoned by Application Framework. The development idea of the API is more clear: Starting from the program entry WinMain, register window recisterclass, and then generate window CREATEWINDOW, get the message getMessage, distinguish the message DispatchMessage, then determine how to handle the message WndProc. The above is a fixed mode, as for the implementation of the application function, completes through a wide variety of API functions. The following learning is performed by the SDK example of the MSDN and the reference "Windows Core Program".