The client and the server can connect successfully, when one of them is closed, another will be normal notified
I've met the question is: when the client sends a message to the server, sending is successful, the service side but no response, no trigger FD_READ, I wondered, if I which step is wrong, but I see online are almost so write ah, please help me see what problem, thank you very much!

The code is as follows:
Server:

 
//Service. The CPP: Defines the entry point for the application. The 
//

# include "stdafx. H" 
#include  
# include "resource. H" 
#include  

# define WM_SOCKET WM_USER + 1 


BOOL CALLBACK DialogService (HWND hwndDlg, UINT uMsg, WPARAM WPARAM, LPARAM LPARAM); 

The SOCKET g_Client; 

Int APIENTRY WinMain (HINSTANCE HINSTANCE, 
HINSTANCE hPrevInstance, 
LPSTR lpCmdLine, 
Int nCmdShow) 
{
//TODO: Place code here. 
HWND Window=CreateDialog (hInstance, MAKEINTRESOURCE (IDD_SERVICE), NULL, DialogService); 
WSADATA wd; 
WSAStartup (0 x0202, & amp; Wd); 

SOCKET sListen=SOCKET (AF_INET SOCK_STREAM, IPPROTO_TCP); 
Int the error=0; 
If (SOCKET_ERROR==sListen) 
{
Error=WSAGetLastError (); 
return -1; 
} 


SOCKADDR_IN sock_in; 
Sock_in. Sin_family=AF_INET; 
Sock_in. Sin_addr. S_un. S_addr=inet_addr (" 127.0.0.1 "); 
Sock_in. Sin_port=htons (5050); 



If (SOCKET_ERROR==bind (sListen, (SOCKADDR *) & amp; Sock_in, sizeof (sock_in))) 
{
Error=WSAGetLastError (); 
return -1; 
} 


If (SOCKET_ERROR==listen (sListen, 3)) 
{
Error=WSAGetLastError (); 
return -1; 
} 

If (SOCKET_ERROR==WSAAsyncSelect (sListen, Window, WM_SOCKET FD_ACCEPT | FD_CLOSE)) 
{
Error=WSAGetLastError (); 
return -1; 
} 


SendDlgItemMessage (Window, IDC_LIST1 LB_ADDSTRING, 0, LPARAM (" start Listen... ")); 

MSG MSG. 
While (GetMessage (& amp; MSG, NULL, 0, 0)) 
{
TranslateMessage (& amp; MSG); 
DispatchMessage (& amp; MSG); 
} 

return 0; 
} 



BOOL CALLBACK DialogService (HWND hwndDlg, UINT uMsg, WPARAM WPARAM, LPARAM LPARAM) 
{
The switch (uMsg) 
{
Case WM_SOCKET: 
{
If (WSAGETASYNCERROR (lParam)) 
{
Closesocket (wParam); 
SendDlgItemMessage (hwndDlg, IDC_LIST1 LB_ADDSTRING, 0, LPARAM (" disconnected with the customer!" )); 
break; 
} 
The switch (WSAGETSELECTEVENT (lParam)) 
{
Case FD_ACCEPT: 
{
G_Client=accept (wParam, NULL, NULL); 
If (SOCKET_ERROR==g_Client) 
{
break; 
} 
If (SOCKET_ERROR==WSAAsyncSelect (wParam, hwndDlg WM_SOCKET, FD_READ | FD_WRITE | FD_CLOSE)) 
{
break; 
} 
SendDlgItemMessage (hwndDlg, IDC_LIST1 LB_ADDSTRING, 0, LPARAM (" accept success! ")); 
} 
break; 
Case FD_READ: 
{
Char szBuf [30]=""; 
If (SOCKET_ERROR==recv (wParam, szBuf, 30, 0)) 
{
SendDlgItemMessage (hwndDlg, IDC_LIST1 LB_ADDSTRING, 0, LPARAM (szBuf)); 
InvalidateRect (GetDlgItem (hwndDlg IDC_LIST1), NULL, TRUE); 
break; 
} 
} 
break; 
Case FD_WRITE: 
{
Char szBuf [30]=""; 
GetWindowText (GetDlgItem (hwndDlg IDC_INPUT), szBuf, 30); 
SetWindowText (GetDlgItem (hwndDlg IDC_INPUT), ""); 

Int result=send (wParam szBuf, strlen (szBuf) + 1, 0). 
If (SOCKET_ERROR==result) 
{
Closesocket (wParam); 
return -1; 
} 
//SendDlgItemMessage (hwndDlg, IDC_LIST1 LB_ADDSTRING, 0, LPARAM (szBuf)); 
} 
break; 
Case FD_CLOSE: 
{
Closesocket (wParam); 
break; 
} 
break; 
} 
} 
break; 
Case WM_COMMAND: 
{
If (BN_CLICKED==HIWORD (wParam)) 
{
If (LOWORD (wParam)==IDC_SEND) 
{
SendMessage (hwndDlg WM_SOCKET, g_Client FD_WRITE); 
} 
} 
} 
break; 
Case WM_CLOSE: 
The DestroyWindow (hwndDlg); 
break; 
Case WM_DESTROY: 
The PostQuitMessage (NULL). 
break; 
Default: 
return FALSE; 
} 
Return TRUE; 
} 

Client:

 
//Client. CPP: Defines the entry point for the application. The 
//

# include "stdafx. H" 
#include  
# include "resource. H" 
#include  
#include  
# define WM_SOCKET WM_USER + 1 


BOOL CALLBACK DialogClient (HWND hwndDlg, UINT uMsg, WPARAM WPARAM, LPARAM LPARAM); 

The SOCKET g_Client; 
SOCKADDR_IN g_sock_in; 


Int APIENTRY WinMain (HINSTANCE HINSTANCE, 
HINSTANCE hPrevInstance, 
LPSTR lpCmdLine, 
Int nCmdShow) 
{
//TODO: Place code here. 

The HWND Window; 

The Window=CreateDialog (hInstance, MAKEINTRESOURCE (IDD_DIALOG1), NULL, DialogClient); 

WSADATA wd; 
WSAStartup (0 x0202, & amp; Wd); 

G_Client=socket (AF_INET SOCK_STREAM, IPPROTO_TCP); 
Int the error=0; 
If (SOCKET_ERROR==g_Client) 
{
Error=WSAGetLastError (); 
return -1; 
} 


G_sock_in. Sin_family=AF_INET; 
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