L_InetConnect

#include "l_bitmap.h"
#include "ltnet.h"

L_LTNET_API L_INT L_InetConnect(pszAddress, nPort, phComputer, pfnCallback, pUserData)

L_CHAR * pszAddress;

/* address of the computer to which to connect */

L_INT nPort;

/* port on remote computer to which to connect */

L_COMP * phComputer;

/* address of variable to update */

INETCALLBACK pfnCallback;

/* pointer to a callback function */

L_VOID *pUserData;

/* user defined callback data */

Connects to a remote computer.

Parameter

Description

pszAddress

Character string containing the address of the computer to which you want to connect

nPort

Port on the remote computer to which to connect

phComputer

Address of variable to be updated with the handle of the connected computer

pfnCallback

Pointer to a callback function of type INETCALLBACK for receiving messages for phComputer. Use the function pointer to your callback function as the value of this parameter.

pUserData

Void pointer that you can use to pass one or more additional parameters that the callback function needs.

 

To use this feature, assign a value to a variable or create a structure that contains as many fields as you need. Then, in this parameter, pass the address of the variable or structure, casting it to L_VOID  *. The callback function, which receives the address in its own pUserData parameter, can cast it to a pointer of the appropriate data type to access your variable or structure.

 

If the additional parameters are not needed, you can pass NULL in this parameter.

Returns

SUCCESS

The function was successful.

< 1

An error occurred. Refer to Return Codes.

Comments

This function requests a connection to a remote computer. The remote computer must accept the connection by calling L_InetAcceptConnect.

If the connection is successful phComputer is updated with the handle to the connected computer. phComputer can then be used with the other internet functions that require a handle to a computer.

pszAddress can be any URL or an IP address in the Internet dot notation. Ex. http://www.leadtools.com or 207.238.49.130.

The INETCALLBACK function will be called when a connection request is successfully accepted by the remote computer.

Immediately after successfully connecting to a LEADTOOLS server started with L_InetServerInit, the INETCALLBACK function will be called. If auto process is enabled, the message will be INET_USER1_RECEIVED and pBuffer will contain a NULL terminated string containing "LEAD Technologies Server X.X" where X.X is the server version number. If auto process is not enabled, the message will be INET_DATA_READY, and the version string can be read using L_InetReadData.

You must initialize the LEADTOOLS Internet DLL using L_InetStartUp before calling this function.

Required DLLs and Libraries

LTNET

For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application

See Also

Functions:

L_InetClose, L_InetReadData, L_InetSendData, L_InetSendBitmap, L_InetSendSound, L_InetAutoProcess, L_InetServerInit, L_InetGetHostName, L_InetAcceptConnect, L_InetStartUp, L_InetShutDown

Topics:

Internet Functions

Example

L_INT EXT_CALLBACK InetCallback(L_COMP   hComp,
                                L_INT    nMessage,
                                L_INT    nError,
                                L_CHAR * pBuffer,
                                L_UINT32 lSize,
                                L_VOID* pUserData)
{
   UNREFERENCED_PARAMETER(pBuffer);
   UNREFERENCED_PARAMETER(lSize);
   UNREFERENCED_PARAMETER(pUserData);

   L_TCHAR s[100]; /* set up a buffer to retrieve the name of the server */
   L_SIZE_T sizeof_s = sizeof(s); /* the size of s */

   switch(nMessage)
   {
      case INET_CONNECT: 
         /* check the status and try to get server's name */
         if(nError == SUCCESS)
         {
            /* now you can assume you are connected to computer 'hComp' */
            if(L_InetGetHostName(hComp, (L_CHAR*) s, HOST_NAME_IP, &sizeof_s) == SUCCESS)
            {
               MessageBox(NULL, TEXT("You have successfully connected to"), s, MB_OK);
            }
            /* do whatever you want to do with the server here ... */

            /* remove the next line if you want to keep the connection open */
            L_InetClose(hComp, TRUE);
         }
         else
            MessageBox(NULL, TEXT("You have failed to connect!"), TEXT("Error"), MB_OK);
         break;
   }
   return SUCCESS;
}

 L_INT InetConnectExample(L_COMP hComp)
{
   L_INT nRet;
   /* Note: instead of server_address you need to put the IP address
      of the computer running the server. You can also put in
      the computer name, if the server is running on a local network */
   /* you do not need to use MakeProcInstance for 32 bit applications */

   nRet = L_InetConnect("207.238.49.190", 1000, &hComp, (INETCALLBACK) InetCallback, NULL);
   if(nRet != SUCCESS)
   {
      MessageBox(NULL, TEXT("Error attempting to connect"), TEXT("ERROR"), MB_OK);
      return nRet;
   }
   return SUCCESS;
}