可选在参数中指定错误代码,
返回值为错误信息,错误码,
没有错误则返回null
错误信息中文版
_WSAEACCES=10013
_WSAEADDRINUSE=10048
_WSAEADDRNOTAVAIL=10049
_WSAEAFNOSUPPORT=10047
_WSAEALREADY=10037
_WSAEBADF=10009
_WSAECONNABORTED=10053
_WSAECONNREFUSED=10061
_WSAECONNRESET=10054
_WSAEDESTADDRREQ=10039
_WSAEDQUOT=10069
_WSAEFAULT=10014
_WSAEHOSTDOWN=10064
_WSAEHOSTUNREACH=10065
_WSAEINPROGRESS=10036
_WSAEINTR=10004
_WSAEINVAL=10022
_WSAEISCONN=10056
_WSAELOOP=10062
_WSAEMFILE=10024
_WSAEMSGSIZE=10040
_WSAENAMETOOLONG=10063
_WSAENETDOWN=10050
_WSAENETRESET=10052
_WSAENETUNREACH=10051
_WSAENOBUFS=10055
_WSAENOTCONN=10057
_WSAENOTEMPTY=10066
_WSAENOTSOCK=10038
_WSAEOPNOTSUPP=10045
_WSAEPFNOSUPPORT=10046
_WSAEPROCLIM=10067
_WSAEPROTONOSUPPORT=10043
_WSAEPROTOOPT=10042
_WSAEPROTOTYPE=10041
_WSAEREMOTE=10071
_WSAESHUTDOWN=10058
_WSAESOCKTNOSUPPORT=10044
_WSAESTALE=10070
_WSAETIMEDOUT=10060
_WSAETOOMANYREFS=10059
_WSAEUSERS=10068
_WSAEWOULDBLOCK=10035
_WSANOTINITIALISED=10093
_WSASYSNOTREADY=10091
_WSAVERNOTSUPPORTED=10092