In This Topic ▼

L_TwainEnableDuplex

Summary

Enables or disables the duplex mode.

Syntax

#include "lttwn.h"

L_LTTWN_API L_INT L_TwainEnableDuplex(hSession, bEnableDuplex)

Parameters

HTWAINSESSION hSession

Handle to an existing TWAIN session. This handle is obtained by calling the L_TwainInitSession or L_TwainInitSession2 function.

L_BOOL bEnableDuplex

Flag that indicates whether to enable or disable the duplex mode. Possible values are:

Value	Meaning
TRUE	Enable the duplex mode.
FALSE	Disable the duplex mode.

Returns

Value	Meaning
SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

L_TwainEnableDuplex internally sets the duplex-enabled capability CAP_DUPLEXENABLED. For more information on these capabilities, refer to the TWAIN specification.

To get the current values of these capabilities, call the L_TwainGetDuplexOptions function.

This function should be called after calling the L_TwainStartCapsNeg function and before calling the L_TwainEndCapsNeg function.

Required DLLs and Libraries

LTTWN
For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files to be Included with your Application.

Example

L_INT TwainEnableDuplexExample(HTWAINSESSION hSession) 
{ 
   L_INT nRet; 
   L_BOOL bEnableDuplex; 
   L_INT nDuplexMode; 
 
   nRet = L_TwainStartCapsNeg(hSession); 
   if(nRet != SUCCESS) 
      return nRet;  
 
   nRet = L_TwainGetDuplexOptions (hSession, &bEnableDuplex, &nDuplexMode); 
   if(nRet != SUCCESS) 
      return nRet; 
   if (bEnableDuplex != TRUE) 
   { 
      nRet = L_TwainEnableDuplex(hSession, TRUE); 
      if(nRet != SUCCESS) 
         return nRet; 
   } 
 
   L_INT nMaxXfer; 
   nRet = L_TwainGetMaxXferCount (hSession, &nMaxXfer); 
   if(nRet != SUCCESS) 
      return nRet; 
   if (nMaxXfer != 10)  
   { 
      nRet = L_TwainSetMaxXferCount (hSession, 10); 
      if(nRet != SUCCESS) 
         return nRet; 
   } 
 
   nRet = L_TwainEndCapsNeg (hSession); 
   if(nRet != SUCCESS) 
      return nRet; 
   return SUCCESS; 
}