TCP服务器（单客户端）

1. 获取本地主机的IP和端口号

若本地主机有多个IP地址，则需要获取本地主机所有IP地址，指定某个IP地址用于创建服务器。

	char **addresses = NULL;
	char addr_arr[10][20] = {0};
	int numAddresses;
	GetAllTCPHostAddresses (&addresses, &numAddresses);
	/* Use the address strings... */
	for (int index = 0; index < numAddresses; index++)
	{
		strcpy (addr_arr [index], addresses [index]);  //copy all address to array
		TCPFreeMemory (addresses[index]);  //Free address string
	}
	TCPFreeMemory (addresses);  //Free addresses array

2. 注册TCP服务器

有了IP和端口号，就可以注册TCP服务器。

if (RegisterTCPServerEx (portNum, ServerTCPCB, 0, ip_address) < 0)
	{
		MessagePopup("TCP Server", "Server registration failed!");
	}

ServerTCPCB指向处理客户端请求的同步回调函数的指针。

3. TCP服务器和客户端的通讯

/* tcp服务器回调函数原型 */
int (*tcpFuncPtr) (unsigned handle, int xType, int errCode, void *callbackData);
//unsigned handle ：句柄 ???
//int xType :接收事件类型（TCP_CONNECT、TCP_DISCONNECT、TCP_DATAREADY）
//int errCode:用于判断TCP_DISCONNECT的原因

tcp服务器回调函数的调用

int CVICALLBACK ServerTCPCB (unsigned handle, int event, int error,void *callbackData)
{
	char receiveBuf[256] = {0};  
	int dataSize = sizeof (receiveBuf) - 1;  //Receive max size is 255 Byte
	char addrBuf[31];
	switch (event)
		{
		case TCP_CONNECT:
			if (g_hconversation)
				{
				/* We already have one client, don't accept another... */
                ;
				tcpChk (DisconnectTCPClient (handle));
				}
			else
				{
				/* Handle this new client connection */
				g_hconversation = handle;
                ;
				/* Set the disconect mode so we do not need to terminate connections ourselves. */
				tcpChk (SetTCPDisconnectMode (g_hconversation, TCP_DISCONNECT_AUTO));
				}
			break;
		case TCP_DATAREADY:
			if ((dataSize = ServerTCPRead (g_hconversation, receiveBuf, dataSize, 1000)) < 0)
				{
				;
				}
			else
				{
				receiveBuf[dataSize] = '\0';
				;
				}
			break;
		case TCP_DISCONNECT:
			if (handle == g_hconversation)
				{
				/* The client we were talking to has disconnected... */
				g_hconversation = 0;
                ;
				/* Note that we do not need to do any more because we set the disconnect mode to AUTO. */
				}
			break;
	}
Done:    
	return 0;
}