1, without running server-side programs, run the client program, black box shows to connect to the server, and send the data to the success,,, what is this???????
2, not the server and the client connection, shown as the server of the black box in a constant state of display is listening, can't show that the connection is successful; The client's black box shows data sent successfully at the same time,,,
Program the following
The client

//* client 
# define WIN32_LEAN_AND_MEAN 

#include  
#include  
#include  
#include  
#include  


//Need to link with Ws2_32. Lib, Mswsock. Lib, and Advapi32. Lib 
# pragma comment (lib, "Ws2_32. Lib") 
# pragma comment (lib, "Mswsock. Lib") 
# pragma comment (lib, "AdvApi32. Lib") 


# define DEFAULT_BUFLEN 512 
# define DEFAULT_PORT "27015" 

Int __cdecl main (int arg c, char * * argv) 
{
WSADATA WSADATA; 
The SOCKET ConnectSocket=INVALID_SOCKET; 
Struct addrinfo * result=NULL, 
* PTR=NULL, 
Hints. 
Char * sendbuf="this is a test"; 
Char recvbuf [DEFAULT_BUFLEN]; 
Int iResult; 
Int recvbuflen=DEFAULT_BUFLEN; 
Printf (" the from client: \ n "); 

//Validate the parameters 
/* if (arg c!=2) {
Printf (" server - the name usage: % s \ n ", argv [0]). 
return 1; 
} */

//Initialize Winsock 
//The WSAStartup function is called to initiate The use of WS2_32. DLL. 
IResult=WSAStartup (MAKEWORD (2, 2), & amp; WsaData); 
If (iResult!=0) {
Printf (" WSAStartup failed with error: % d \ n ", iResult); 
return 1; 
} 

ZeroMemory (& amp; Hints, sizeof (hints)); 
Hints. Ai_family=AF_UNSPEC; 
Hints. Ai_socktype=SOCK_STREAM; 
Hints. Ai_protocol=IPPROTO_TCP; 

//Resolve the server address and port 
IResult=getaddrinfo (" localhost ", DEFAULT_PORT, & amp; Hints, & amp; The result); 
If (iResult!=0) {
Printf (" getaddrinfo failed with error: % d \ n ", iResult); 
WSACleanup (); 
return 1; 
} 

//Attempt to connect to an address until one succeeds 
For (PTR=the result; PTR!=NULL; PTR=PTR - & gt; Ai_next) {

//Create a SOCKET for connecting to the server 
ConnectSocket=socket (PTR - & gt; Ai_family, PTR - & gt; Ai_socktype, 
PTR - & gt; Ai_protocol); 
If (ConnectSocket==INVALID_SOCKET) {
Printf (" socket failed with error: % ld \ n ", WSAGetLastError ()); 
WSACleanup (); 
return 1; 
} 

//Connect to server. 
IResult=connect (ConnectSocket, PTR - & gt; Ai_addr, (int) PTR - & gt; Ai_addrlen); 
If (iResult==SOCKET_ERROR) {
Closesocket (ConnectSocket); 
ConnectSocket=INVALID_SOCKET; 
continue; 
} 
break; 
} 

Freeaddrinfo (result); 
Printf (" jump out of the loop! \n"); 

If (ConnectSocket==INVALID_SOCKET) {
Printf (" Unable to connect to server! \n"); 
WSACleanup (); 
return 1; 
} 
Printf (" connect success \ n "); 

//Send an initial buffer 
IResult=send (ConnectSocket, sendbuf, (int) strlen (sendbuf), 0). 
If (iResult==SOCKET_ERROR) {
Printf (" send failed with error: % d \ n ", WSAGetLastError ()); 
Closesocket (ConnectSocket); 
WSACleanup (); 
return 1; 
} 

Printf (" Bytes Sent: % ld \ n ", iResult); 
Printf (" sending content: % s \ n ", sendbuf); 

//shutdown the connection since no more data will be sent 
IResult=shutdown (ConnectSocket SD_SEND); 
If (iResult==SOCKET_ERROR) {
Printf (" shutdown failed with error: % d \ n ", WSAGetLastError ()); 
Closesocket (ConnectSocket); 
WSACleanup (); 
return 1; 
} 

//the Receive until the peer closes the connection 
Do {

IResult=recv (ConnectSocket, recvbuf recvbuflen, 0). 
If (iResult & gt; 0) 
Printf (" Bytes received: % d \ n ", iResult); 
Else if (iResult==0) 
Printf (" Connection closed \ n "); 
The else 
Printf (" recv failed with error: % d \ n ", WSAGetLastError ()); 

} while (iResult & gt; 0); 

//the cleanup 
Closesocket (ConnectSocket); 
WSACleanup (); 
getchar(); 
return 0; 
} 

The server side
UNICODE

 # undef
# define WIN32_LEAN_AND_MEAN 

#include  
#include  
#include  
#include  
#include  

//Need to link with Ws2_32. Lib 
# pragma comment (lib, "Ws2_32. Lib") 
//# pragma comment (lib, "Mswsock. Lib") 

# define DEFAULT_BUFLEN 512 
# define DEFAULT_PORT "27015" 

Int __cdecl main (void) 
{
WSADATA WSADATA; 
Int iResult; 

The SOCKET ListenSocket=INVALID_SOCKET; 
The SOCKET ClientSocket=INVALID_SOCKET; 

Struct addrinfo * result=NULL; 
Struct addrinfo hints. 

Int iSendResult; 
Char recvbuf [DEFAULT_BUFLEN]; 
Int recvbuflen=DEFAULT_BUFLEN; 
Printf (" the from server: \ n "); 
//Initialize Winsock 
IResult=WSAStartup (MAKEWORD (2, 2), & amp; WsaData); 
If (iResult!=0) {
Printf (" WSAStartup failed with error: % d \ n ", iResult); 
return 1; 
} 

ZeroMemory (& amp; Hints, sizeof (hints)); 
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