windows平台socket编程编译错误error C2065: ‘SOCKET‘ : undeclared identifier

error C2065: 'SOCKET' : undeclared identifier

LPFN_ACCEPTEX' : undeclared identifier

error C2011: 'sockaddr_in' : 'struct' type redefinition

写代码的时候要用到SOCKET、LPFN_ACCEPTEX、WSA系列api，也就是会用到

#define WIN32_LEAN_AND_MEAN

#include #include #include #include

#pragma comment(lib, "ws2_32")

一开始不是这种include的顺序，也没有定义WIN32_LEAN_AND_MEAN，提示各种重定义和未定义

换成这种include顺序之后，重定义和未定义错误就没了。

Using the Windows Headers - Win32 apps | Microsoft Docs

根据微软官方的描述，定义WIN32_LEAN_AND_MEAN之后就不包含一些非必要的组件

You can reduce the size of the Windows header files by excluding some of the less common API declarations as follows:

Define WIN32_LEAN_AND_MEAN to exclude APIs such as Cryptography, DDE, RPC, Shell, and Windows Sockets.

#define WIN32_LEAN_AND_MEAN

Define one or more of the NOapi symbols to exclude the API. For example, NOCOMM excludes the serial communication API. For a list of support NOapi symbols, see Windows.h.

#define NOCOMM

这样编译会更小更快

可能还有区分宏定义的作用，加了这个宏之后，一些未定义的错误就没了