工程中添加 Winsock2.h 报错
1>c:program files (x86)windows kits8.1includesharedws2def.h(100): warning C4005: 'AF_IPX' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(452) : see previous definition of 'AF_IPX'
1>c:program files (x86)windows kits8.1includesharedws2def.h(140): warning C4005: 'AF_MAX' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(471) : see previous definition of 'AF_MAX'
1>c:program files (x86)windows kits8.1includesharedws2def.h(177): warning C4005: 'SO_DONTLINGER' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(394) : see previous definition of 'SO_DONTLINGER'
1>c:program files (x86)windows kits8.1includesharedws2def.h(221): error C2011: 'sockaddr' : 'struct' type redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(477) : see declaration of 'sockaddr'
1>c:program files (x86)windows kits8.1includesharedws2def.h(421): error C2059: syntax error : 'constant'
1>c:program files (x86)windows kits8.1includesharedws2def.h(421): error C3805: 'constant': unexpected token, expected either '}' or a ','
1>c:program files (x86)windows kits8.1includesharedws2def.h(556): warning C4005: 'IN_CLASSA' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(279) : see previous definition of 'IN_CLASSA'
1>c:program files (x86)windows kits8.1includesharedws2def.h(562): warning C4005: 'IN_CLASSB' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(285) : see previous definition of 'IN_CLASSB'
1>c:program files (x86)windows kits8.1includesharedws2def.h(568): warning C4005: 'IN_CLASSC' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(291) : see previous definition of 'IN_CLASSC'
1>c:program files (x86)windows kits8.1includesharedws2def.h(579): warning C4005: 'INADDR_ANY' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(296) : see previous definition of 'INADDR_ANY'
1>c:program files (x86)windows kits8.1includesharedws2def.h(581): warning C4005: 'INADDR_BROADCAST' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(298) : see previous definition of 'INADDR_BROADCAST'
1>c:program files (x86)windows kits8.1includesharedws2def.h(615): error C2011: 'sockaddr_in' : 'struct' type redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(304) : see declaration of 'sockaddr_in'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(136): error C2011: 'fd_set' : 'struct' type redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(60) : see declaration of 'fd_set'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(156): warning C4005: 'FD_CLR' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(89) : see previous definition of 'FD_CLR'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(171): warning C4005: 'FD_SET' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(94) : see previous definition of 'FD_SET'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(180): error C2011: 'timeval' : 'struct' type redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(103) : see declaration of 'timeval'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(236): error C2011: 'hostent' : 'struct' type redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(159) : see declaration of 'hostent'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(249): error C2011: 'netent' : 'struct' type redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(172) : see declaration of 'netent'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(256): error C2011: 'servent' : 'struct' type redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(179) : see declaration of 'servent'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(268): error C2011: 'protoent' : 'struct' type redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(191) : see declaration of 'protoent'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(364): error C2011: 'WSAData' : 'struct' type redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(314) : see declaration of 'WSAData'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(462): error C2011: 'sockproto' : 'struct' type redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(486) : see declaration of 'sockproto'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(504): error C2011: 'linger' : 'struct' type redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(523) : see declaration of 'linger'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(517): warning C4005: 'SOMAXCONN' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(536) : see previous definition of 'SOMAXCONN'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(551): warning C4005: 'FD_READ' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(554) : see previous definition of 'FD_READ'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(554): warning C4005: 'FD_WRITE' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(555) : see previous definition of 'FD_WRITE'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(557): warning C4005: 'FD_OOB' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(556) : see previous definition of 'FD_OOB'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(560): warning C4005: 'FD_ACCEPT' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(557) : see previous definition of 'FD_ACCEPT'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(563): warning C4005: 'FD_CONNECT' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(558) : see previous definition of 'FD_CONNECT'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(566): warning C4005: 'FD_CLOSE' : macro redefinition
1> c:program files (x86)windows kits8.1includeumwinsock.h(559) : see previous definition of 'FD_CLOSE'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(1650): error C2375: 'accept' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(734) : see declaration of 'accept'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(1672): error C2375: 'bind' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(739) : see declaration of 'bind'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(1691): error C2375: 'closesocket' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(744) : see declaration of 'closesocket'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(1710): error C2375: 'connect' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(746) : see declaration of 'connect'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(1731): error C2375: 'ioctlsocket' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(751) : see declaration of 'ioctlsocket'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(1752): error C2375: 'getpeername' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(756) : see declaration of 'getpeername'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(1773): error C2375: 'getsockname' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(761) : see declaration of 'getsockname'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(1796): error C2375: 'getsockopt' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(766) : see declaration of 'getsockopt'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(1817): error C2375: 'htonl' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(773) : see declaration of 'htonl'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(1834): error C2375: 'htons' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(775) : see declaration of 'htons'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(1852): error C2375: 'inet_addr' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(777) : see declaration of 'inet_addr'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(1870): error C2375: 'inet_ntoa' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(779) : see declaration of 'inet_ntoa'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(1971): error C2375: 'listen' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(781) : see declaration of 'listen'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(1989): error C2375: 'ntohl' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(785) : see declaration of 'ntohl'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2006): error C2375: 'ntohs' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(787) : see declaration of 'ntohs'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2026): error C2375: 'recv' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(789) : see declaration of 'recv'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2051): error C2375: 'recvfrom' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(795) : see declaration of 'recvfrom'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2077): error C2375: 'select' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(803) : see declaration of 'select'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2101): error C2375: 'send' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(810) : see declaration of 'send'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2126): error C2375: 'sendto' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(816) : see declaration of 'sendto'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2152): error C2375: 'setsockopt' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(824) : see declaration of 'setsockopt'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2174): error C2375: 'shutdown' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(831) : see declaration of 'shutdown'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2195): error C2375: 'socket' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(835) : see declaration of 'socket'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2220): error C2375: 'gethostbyaddr' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(842) : see declaration of 'gethostbyaddr'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2240): error C2375: 'gethostbyname' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(847) : see declaration of 'gethostbyname'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2258): error C2375: 'gethostname' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(849) : see declaration of 'gethostname'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2298): error C2375: 'getservbyport' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(853) : see declaration of 'getservbyport'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2317): error C2375: 'getservbyname' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(857) : see declaration of 'getservbyname'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2335): error C2375: 'getprotobynumber' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(861) : see declaration of 'getprotobynumber'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2352): error C2375: 'getprotobyname' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(863) : see declaration of 'getprotobyname'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2373): error C2375: 'WSAStartup' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(867) : see declaration of 'WSAStartup'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2392): error C2375: 'WSACleanup' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(871) : see declaration of 'WSACleanup'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2409): error C2375: 'WSASetLastError' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(873) : see declaration of 'WSASetLastError'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2426): error C2375: 'WSAGetLastError' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(875) : see declaration of 'WSAGetLastError'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2447): error C2375: 'WSAIsBlocking' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(877) : see declaration of 'WSAIsBlocking'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2465): error C2375: 'WSAUnhookBlockingHook' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(879) : see declaration of 'WSAUnhookBlockingHook'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2483): error C2375: 'WSASetBlockingHook' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(881) : see declaration of 'WSASetBlockingHook'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2501): error C2375: 'WSACancelBlockingCall' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(883) : see declaration of 'WSACancelBlockingCall'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2524): error C2375: 'WSAAsyncGetServByName' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(885) : see declaration of 'WSAAsyncGetServByName'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2552): error C2375: 'WSAAsyncGetServByPort' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(893) : see declaration of 'WSAAsyncGetServByPort'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2579): error C2375: 'WSAAsyncGetProtoByName' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(901) : see declaration of 'WSAAsyncGetProtoByName'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2605): error C2375: 'WSAAsyncGetProtoByNumber' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(908) : see declaration of 'WSAAsyncGetProtoByNumber'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2631): error C2375: 'WSAAsyncGetHostByName' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(915) : see declaration of 'WSAAsyncGetHostByName'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2659): error C2375: 'WSAAsyncGetHostByAddr' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(922) : see declaration of 'WSAAsyncGetHostByAddr'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2683): error C2375: 'WSACancelAsyncRequest' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(931) : see declaration of 'WSACancelAsyncRequest'
1>c:program files (x86)windows kits8.1includeumwinsock2.h(2704): error C2375: 'WSAAsyncSelect' : redefinition; different linkage
1> c:program files (x86)windows kits8.1includeumwinsock.h(933) : see declaration of 'WSAAsyncSelect'
解决方法：
包含#include <Winsock2.h>在#include <windows.h>之前