什么是API－－所谓API本来是为C和C++程序员写的。API说来说去，就是一 种函数，他们包含在一个附加名为DLL的动态连接库文件中。-What is API? API is sort for Application Programming Interface. It is not only for C/C++ Programmer, but also for other programming language. Usually, we refer to API as Windows API. Generally, it is encapsulated in a DLL file.